High-speed hobbing:
Competitive global market requires gear manufacturers to reduce production costs while increasing productivity. This means that the hob hobbing to achieve higher speed and feed rate. This requires the help of high-quality materials, high-performance coatings. Because high-quality tools usually means high prices, and some Machine Shop in not analyzing all aspects of the production process to determine the really important factors - the production cost of each part of the total cost - to reject the case of high-performance roll knives.
To achieve a higher gear cutting tool productivity requirements have led designers to develop high-performance, multi-threaded, shank-type hobs. Shank-type hobs material manufactured using the whole tool steel bars. Usually smaller in diameter, generally longer than the hole cutter. When installed on a hobbing machine, by the journal in both ends fixed, rather than hole cutter mounted on a mandrel so.
Shank-type tool commonly used in the overall processing of worm, the worm requires hob diameter close to the diameter. Shank-type hobs best optimized for high volume production applications. Large diameter, large module gear, such as truck transmissions, or for mining machinery, etc., usually hole cutter production.
Shank-type hobs form the length of the rotation may want to cut a large area, each of the hob can cut a lot of parts. Reduced shank-type hobs and female factors, including cutting time increased feed rate and cutter speed and the number of threads on the hob. Test the tool designer "shank cutter reason is because the production rate in each channel along the hob cutting more rotation position, due to the hob and tool coating wear resistance of materials to improve the cutting frequency increased, so More parts can be processed.
Hobbing process can be with or without coolant in the circumstances. However, many users tend to be dry roll, because it avoids environmental problems and eliminate clean-up costs related to the cooling fluid. Dry cutting requires that they have high-quality coated hob, with high temperature stability and low thermal conductivity, in order to protect the dry, high-speed hobbing conditions of the cutting edge.
As for the integral shank-type hobs, and installed in the machine parts used in fewer components compared to the hob with the hole, their higher rigidity. Installed on the hob for the Brothers, installation and testing between the top, it can be detected. Compared with the hole cutter, shank-type hobs eliminates spindle hole and beating between the cumulative tolerance as a result of gaskets and mounting nut vibrations caused the error.Shank-type hobs quality steel and have high wear resistance, both in the cutting room shower or at high temperatures have high hardness. Despite the high quality steel and coated material costs higher than the low performance, but with a smaller diameter shank-type hobs generate higher cutting speed can ensure that each part has a faster cycle times and lower processing costs (see table .) For the application of occasions, this one-piece processing cost of benefits beyond the one-piece general tool to increase the amount of cost. This saves a single piece of the total cost. Single cost comparison summary Gleason hobbing Genesis shank and hole cutter moreApplications: Automotive pinion, 36.46mm diameter, 22 teeth, materials, 8620, hardness 180HB, production of 800,000 piece quantities.
Hob Material / Finish: handle type - carbon / vanadium / cobalt high speed steel / AlNite
Hole - Cobalt bearing high speed steel / AlNiteGenesis shank (baseline) female (compared with the shank)Hob price 100 58One-piece tool costs (including purchase and maintenance costs) 100 57.1Hob speed 10 062Feed rate 100 1.5Total production time and costs 100 214100 216 cutting cycle timeSingle-piece production costs 100 178Coating is the key
In the hob on the use of appropriate coatings can increase productivity and reduce processing costs. Depending on the application, use of appropriate coatings, tool life may be doubled, so the tool can save costs, reduce the number of tool changes, reduce machine downtime.
As hobbing cutting speed and depth of cut in the workpiece with the tensile strength decreased with the increase, and a suitable choice of coating can achieve a higher speed. In some cases, can achieve a higher feed rate. Almost all of the hob is used through a physical vapor deposition (PVD) coating the coating process protection. Standard titanium nitride (TiN) coated with a lubricant in the case of low effective. Titanium carbonitride (TiCN) coating to improve the hardness and wear resistance for abrasive materials. Titanium aluminum nitrogen (TiAlN) coating is used for dry machining, because they have high strength and heat resistance. Recently developed a dry machining of aluminum coated chromium nitrogen (AlCrN), wear resistance, heat resistance and oxidation resistance even higher.
Friday, January 13, 2012
Automotive Gear Manufacturing Technology
Gear manufacturing technology:
Gear cutting and precision according to different structures require different processes. View of the large investment in equipment, process methods usually give full consideration to the choice of existing resources. Gear processing technology of small deformation and stability control is relatively complex, mostly to be used after rough forging isothermal normalizing, in order to obtain good performance and trends of the deformation process uniform microstructure: low speed for less precision cylindrical gear can be hot before shaving and heat is no longer processing: processing of cylindrical gears under conditions of heat Qi teeth and grinding teeth have different ways of selection, clarity tooth profile correction of low cost but weak, high precision grinding, but the high cost: repair edge and the crown gear modification technology to significantly reduce noise and improve the transmission gear engagement performance, currently being widely used. Straight bevel gear is mainly used for low accuracy because of the speed differential is relatively low, the current recommended forging gear. Spiral bevel gear machining and machine adjustment calculation, the past is very complex and time-consuming manual operation has been modern-specific software and computer programs replaced by the introduction of finite element analysis and making the process more reliable and convenient parameter design: heat processing spiral bevel gears there are two kinds of lapping and grinding, grinding teeth because of the high cost, low efficiency and limitations of the currently most used lapping, lapping geometry of the amendment is weak, so the spiral bevel gear driven gear to use more pressure carburization quenching process. Gear materials and heat treatment technology is the control of deformation processing gear challenging task.
Gear Cutting in the simultaneous development of measurement technology to improve the level of gear manufacturing as important. Traditional geometric measurement and comprehensive measurement methods as well as coordinate the development of technology, the emergence of gear measuring center in the measurement accuracy, efficiency, range and other aspects have been greatly improved. Tooth-shaped surface profile measurement space become a reality, such as geometric entities cylindrical gear easily accessible numerical model for the spiral bevel gear tooth profile is difficult to obtain accurate surface before the actual model, is now able to achieve for a variety of shows such as boundary conditions, material PSN curve, heat treatment, the friction factor and other key performance data can be obtained through the pilot testing, and for lubrication, temperature, relative slip velocity and some other important data still need to get in-depth research.
Automotive parts as gears working conditions because of its complexity and uncertainty, not simply by virtue of the precision and the other is to have accurate measurement and analysis methods and means. At present, many domestic manufacturers already have the gear to carry out in-depth study of the conditions.
Divided into top gear tooth modification modification known as tip relief and root modification, Shen cut, committed to addressing the root meshing gear tooth tip and interference problems: to solve hobs, shaving cutters, arc tooth cutter wheel design and trimming. Modification to the main control tooth bearing contact area location and expansion of the state and compensation for changes in temperature cause the helix angle, depending on the purpose and conditions can be used both ends of the modification, the whole tooth modification to the line, drum gear modification, etc. by shaving machines, spiral bevel gear grinding machine and milling machine tool tilt adjustment is completed. The main problem is a reasonable modification of the method validation parameters need to be studied and the experimental basis for modification is not sufficient, the need to establish a viable and continue to improve standards and specifications.
Mechanical parts, gears relatively complex and high manufacturing costs, the pursuit of precision to ensure high performance is the direct consequence of the practice is neither scientific nor reasonable cost. Gear modification methods rely on basic research shaving, milling, grinding and other major process equipment function expansion, can be called "parasitic process", does not require a large investment in technology costs, improve through targeted modification of the use of gear performance, on the one hand to play as much as possible the potential of the gear itself, on the other hand a reasonable choice of gear production control accuracy, reduce process costs. In-depth study of the application of cost-effective technology for improving gear meaning is obvious.
Gear cutting and precision according to different structures require different processes. View of the large investment in equipment, process methods usually give full consideration to the choice of existing resources. Gear processing technology of small deformation and stability control is relatively complex, mostly to be used after rough forging isothermal normalizing, in order to obtain good performance and trends of the deformation process uniform microstructure: low speed for less precision cylindrical gear can be hot before shaving and heat is no longer processing: processing of cylindrical gears under conditions of heat Qi teeth and grinding teeth have different ways of selection, clarity tooth profile correction of low cost but weak, high precision grinding, but the high cost: repair edge and the crown gear modification technology to significantly reduce noise and improve the transmission gear engagement performance, currently being widely used. Straight bevel gear is mainly used for low accuracy because of the speed differential is relatively low, the current recommended forging gear. Spiral bevel gear machining and machine adjustment calculation, the past is very complex and time-consuming manual operation has been modern-specific software and computer programs replaced by the introduction of finite element analysis and making the process more reliable and convenient parameter design: heat processing spiral bevel gears there are two kinds of lapping and grinding, grinding teeth because of the high cost, low efficiency and limitations of the currently most used lapping, lapping geometry of the amendment is weak, so the spiral bevel gear driven gear to use more pressure carburization quenching process. Gear materials and heat treatment technology is the control of deformation processing gear challenging task.
Gear Cutting in the simultaneous development of measurement technology to improve the level of gear manufacturing as important. Traditional geometric measurement and comprehensive measurement methods as well as coordinate the development of technology, the emergence of gear measuring center in the measurement accuracy, efficiency, range and other aspects have been greatly improved. Tooth-shaped surface profile measurement space become a reality, such as geometric entities cylindrical gear easily accessible numerical model for the spiral bevel gear tooth profile is difficult to obtain accurate surface before the actual model, is now able to achieve for a variety of shows such as boundary conditions, material PSN curve, heat treatment, the friction factor and other key performance data can be obtained through the pilot testing, and for lubrication, temperature, relative slip velocity and some other important data still need to get in-depth research.
Automotive parts as gears working conditions because of its complexity and uncertainty, not simply by virtue of the precision and the other is to have accurate measurement and analysis methods and means. At present, many domestic manufacturers already have the gear to carry out in-depth study of the conditions.
Divided into top gear tooth modification modification known as tip relief and root modification, Shen cut, committed to addressing the root meshing gear tooth tip and interference problems: to solve hobs, shaving cutters, arc tooth cutter wheel design and trimming. Modification to the main control tooth bearing contact area location and expansion of the state and compensation for changes in temperature cause the helix angle, depending on the purpose and conditions can be used both ends of the modification, the whole tooth modification to the line, drum gear modification, etc. by shaving machines, spiral bevel gear grinding machine and milling machine tool tilt adjustment is completed. The main problem is a reasonable modification of the method validation parameters need to be studied and the experimental basis for modification is not sufficient, the need to establish a viable and continue to improve standards and specifications.
Mechanical parts, gears relatively complex and high manufacturing costs, the pursuit of precision to ensure high performance is the direct consequence of the practice is neither scientific nor reasonable cost. Gear modification methods rely on basic research shaving, milling, grinding and other major process equipment function expansion, can be called "parasitic process", does not require a large investment in technology costs, improve through targeted modification of the use of gear performance, on the one hand to play as much as possible the potential of the gear itself, on the other hand a reasonable choice of gear production control accuracy, reduce process costs. In-depth study of the application of cost-effective technology for improving gear meaning is obvious.
Machining hardened steel
Hardened steel-Machining hardened steel
1. What is a hardened steel?
Hardened steel is the metal after quenching, martensite, hardness greater than HRC50 steel. Hardened steel cutting in hard materials occupies a large proportion.
Machining hardened steel is the traditional method of grinding. However, in order to improve processing efficiency, but can not solve the complex shape of the workpiece after grinding and quenching the shape and position error resulting problems often require the use of turning, milling, boring, drilling and reaming and other cutting methods. Hardened steel cutting has the following characteristics:
(1), high hardness, high strength, almost no plastic: This is the main cutting characteristics of hardened steel. When the hardness of hardened steel to HRC50 ~ 60, its strength up to σb = 2100 ~ 2600MPa, according to classification by processing material processing requirements, the hardness and strength of hardened steel are 9a-class, are the most difficult to cut materials.
(2) hardened steel cutting power, cutting temperatures are high: from the high hardness and high strength of the workpiece cut chips, the unit cutting force of up to 4500MPa. In order to improve the cutting conditions, increase heat dissipation area, the smaller the main tool selection and vice declination angle. At this time will cause vibration, required to have a good technology system rigidity.
(3) hardened steel is not easy to BUE: hardened steel, high hardness, brittleness, cutting is not easy to BUE, get a lower surface to be machined surface roughness.
(4) collapse easily broken blade, wear: Because of the brittleness of hardened steel, cutting short the chip and blade contacts, cutting force and cutting tool edge heat concentrated in the near collapse of broken blade easy to make and wear.
(5) Low thermal conductivity: the thermal conductivity is generally hardened steel is 7.12W / (m • K), about 45 steel, 1 / 7. Machinability of the material level is 9a-level, are difficult to cut materials. As low thermal conductivity of hardened steel, the cutting heat is difficult to pass chip away, cutting temperature is high, accelerated tool wear.
2. How to Select hardened steel cutting tool material?
Reasonable choice of cutting tool material is an important condition of hardened steel. According to the characteristics of hardened steel cutting tool materials not only have high hardness, wear resistance, heat resistance, and to have a certain strength and thermal conductivity.
(1) carbide: To improve the performance of cemented carbide, the choice of carbide, should give priority to adding the right amount of TaC or NbC carbide ultrafine particles. Because WC-Co cemented carbide in the class, adding TaC after the original can be improved high temperature strength of 800 ℃ 150 ~ 300MPa, room temperature hardness HV40 ~ 100. After adding NbC, high-temperature strength increased 150 ~ 300MPa, room temperature hardness HV70 ~ 150. And TaC and NbC grain refinement can improve the crater wear resistant carbide ability. TaC can also reduce the friction coefficient, lower cutting temperature, enhanced carbide thermal cracking and thermoplastic deformation capacity, but also the WC grain refinement to 0.5 ~ 1μm, the hardness HRA1.5 ~ 2, bending strength can increase 600 ~ 800MPa, high temperature hardness than carbide.
Used to cut hardened steel, carbide grades are: YM051, YM052, YN05, YN10, 600,610,726,758,767,813 and so on.
(2) hot pressing silicon nitride ceramics and ceramic composites: TiC added in Al2O3 and other metal elements and the use of hot pressing process, to improve the ceramic density, improve the performance of alumina-based ceramics, it's hardness to HRA95.5, bending strength can reach 800 ~ 1200MPa, heat resistance up to 1200 ℃ ~ 1300 ℃, can be used to reduce wear and diffusion bonding. Its main brands are AG2, AG3, AG4, LT35, LT55, AT6 and so on. Si3N4 silicon nitride based ceramics are adding TiC and other metal elements, and its hardness HRA93 ~ 94, the bending strength is 700 ~ 1100MPa. Its main brands are HS73, HS80, F85, ST4, TP4, SM, HDM1, HDM2, HDM3. Both ceramics for turning, milling, boring, planing hardened steel.
(3), cubic boron nitride composite film (PCBN) tool: its hardness HV8000 ~ 9000, composite flexural strength of 900 ~ 1300MPa, relatively high thermal conductivity, heat resistance to 1400 ℃ ~ 1500 ℃, the tool material the highest. It is very suitable for hardened steel, semi-finishing and finishing.
The best hardened steel cutting tool material is cubic boron nitride, followed by composite ceramics, and then followed by the new carbide grades.
3. How to choose the cutting tool geometry parameters of hardened steel?
When cutting hardened steel, having a good tool material, tool geometry without reasonable parameters, they can not achieve satisfactory results. Therefore, according to the specific tool material, workpiece material and cutting conditions, a reasonable choice of tool geometry, in order to effectively play the cutting tool material should have.
(1) front: cutting the size of the anterior horn of the great influence of hardened steel. Since the hardness of hardened steel, high strength, cutting power, and concentrated near the edge of the tool. In order to avoid chipping and playing knife, rake angle should be zero and negative selection, the general γ0 =- 10 ° ~ 0 °. Workpiece material hardness, intermittent cutting, should be selected large negative rake angle, γ0 =- 10 ° ~ -30 °. If you use positive rake angle indexable inserts should grind bγ = 0.5 ~ 1mm wide, γ01 =- 5 ° ~ -15 ° larger negative chamfering, to enhance the edge strength.
(2) horn: hardened steel cutting tools should be higher than normal posterior horn of the posterior horn of the large number of tools to reduce the friction flank, generally α0 = 8 ° ~ 10 ° as well.
(3) the main and sub-declination angle: the tip in order to enhance strength and improve heat dissipation, the main angle κr = 30 ° ~ 60 °, Vice-angle κ'r = 6 ° ~ 15 °.
(4) inclination: blade angle is negative, you can increase tip strength. But the negative is too large, will force Fp increases system rigidity is poor in the process, causing the vibration. So under normal circumstances, λs =- 5 ° ~ 0 °; intermittent cutting, λs =- 10 ° ~ -20 °; hardened hob scraper, it's blade angle λs =- 30 °.
(5) tip radius: it is the size of the impact of tip strength and machined surface roughness. Rigidity due to the impact of process systems, tip radius γε = 0.5 ~ 2mm appropriate.
Hardened steel cutting tools, in a reasonable, based on the selected geometric parameters must be carefully grinding and research Bei, the surface of the grinding tool to improve the quality of the tool life is improved.
4. How to choose when cutting hardened steel cutting?
Machining hardened steel cutting, mainly based tool material, physical and mechanical properties of workpiece material, workpiece shape, rigidity and allowance process system to choose. Three elements in the choice of cutting parameters, first consider selecting a reasonable cutting speed, followed by the depth of cut, and then followed by the feed.
(1) cutting speed: a general heat-resistant hardened steel at 200 ℃ ~ 600 ℃, while the carbide heat resistance of 800 ℃ ~ 1000 ℃, the heat resistance of ceramic tool 1100 ℃ ~ 1200 ℃, cubic nitrogen of the heat resistance of boron 1400 ℃ ~ 1500 ℃. In addition to high-speed steel, in general, hardened steel to about 400 ℃, its hardness began to decline, and the tool material remained its original hardness. So when cutting hardened steel, full use of the above this feature, select the cutting speed should not be too low or too high to maintain the tool has some durability. From the current experience, a different cutting tool materials, cutting hardened steel, carbide cutting tools Vc = 30 ~ 75m/min; ceramic tool Vc = 60 ~ 120m/min; cubic boron nitride cutting tools Vc = 100 ~ 200m / min. In intermittent cutting and workpiece material hardness is too high, should reduce the cutting speed, generally above the lowest cutting speed of about 1 / 2. The best in cutting speed continuous cutting, to cut the chip Chenganhongse appropriate.
(2) depth of cut: general allowance and process systems based on rigid selection, under normal circumstances, αp = 0.1 ~ 3mm.
(3) feed: generally 0.05 ~ 0.4mm / r. The workpiece material hardness or intermittent cutting, in order to reduce the unit cutting force, feed rate should be reduced to prevent chipping and play knife.
5. How hardened steel with a ceramic cutting tool?
Ceramic cutting tool material hardened steel, carbide cutting than hardened steel, has a significant effect. This was reflected in the hardness of ceramic cutting tools and heat resistance than carbide. Use it to create the turning, milling, thread cutting tools, can be successful in cutting hardened steel, its durability is higher than YT05, 643, YM052 carbide.
(1) full ceramic tool material carbide hardness and heat resistance than the high of this feature, select the cutting speed should be higher than the hardened steel cutting carbide cutting speed, generally 50% higher. If the cutting speed 50m/min, the ceramic tool flank wear and carbide close. When cutting speed increased to 95m/min, its wear resistance is much higher than YT05 carbide. Such as the use made of ceramic blade cutter blade on three sides, the cutting speed to 102m/min end milling depth 5.2mm, width 16mm, length 700mm hardened steel keyway, the tool is basically no wear.
(2) ceramic tool in cutting under impact load, the tool should be selected small main angle, or use a large circular arc blade tip to increase tip strength, to avoid tool damage. If using a circular blade made of ceramic machine clip end milling cutter, milling hardened steel, Vc = 120 ~ 150m/min, Vf = 230 ~ 290mm/min, αp = 1 ~ 2mm.
(3) should be negative with negative rake angle and blade angle, in order to facilitate and increase the blade tip strength. Blade and flank roughness Ra is less than 0.4μm.
(4) cutting without cutting fluid generally, to use, throughout the full supply to, or blade cracks due to thermal expansion and contraction.
(5) lower than the bending strength of ceramic cutting tools carbide bending strength, in order to reduce the force per unit area of the tool, cutting feed rate to be smaller, typically f = 0.08 ~ 0.15mm / r.
6. How to use cubic boron nitride cutting tool hardened steel?
Cubic boron nitride cutting tools (CBN) is not only a good material for manufacture of abrasives and grinding it easy (free diamond grinding wheel) is used to make turning tools, boring tools, milling cutters, gun drill, reamer, gear tools such good material. CBN cutting of hardened steel is mainly used, can also be used to cut other difficult to cut materials. It not only has a high metal removal rate, and have a good surface quality. Cutting of hardened steel can be effectively replaced by grinding to reduce the manufacturing processes and improve productivity. Sold on the market of CBN inserts, mostly in the composite film with the form of carbide, indexable inserts made of or tool, its purpose is to increase the flexural strength of CBN inserts.
Because CBN tools, high hardness (HV8000 ~ 9000), high heat resistance (1400 ℃ ~ 1500 ℃), when used several times to allow the cutting speed is higher than the carbide cutting hardened steel, and durability is the hardness of alloy several times to several times. CBN tools when cutting hardened steel and carbide tools compared.
CBN tools suitable for low speed cutting, CBN cutting tool by cutting heat generated in the cutting area within a small softening of workpiece material to cutting.
In the cutting hardness of HRC55 ~ 65 of the material, CBN tool cutting speed should be 50 ~ 120m/min. Milling of the Vc = 100 ~ 160m/min, feed rate per minute, Vf = 70 ~ 160mm/min; reaming when Vc = 60 ~ 130m/min, ap = 0.1 ~ 0.2mm, f = 0.07 ~ 0.2mm / r . CBN tool is mainly used for hardening steel, semi-finishing and finishing. The machined surface is not generated as grinding burns, as the phenomenon is about ten times more efficient than grinding.
1. What is a hardened steel?
Hardened steel is the metal after quenching, martensite, hardness greater than HRC50 steel. Hardened steel cutting in hard materials occupies a large proportion.
Machining hardened steel is the traditional method of grinding. However, in order to improve processing efficiency, but can not solve the complex shape of the workpiece after grinding and quenching the shape and position error resulting problems often require the use of turning, milling, boring, drilling and reaming and other cutting methods. Hardened steel cutting has the following characteristics:
(1), high hardness, high strength, almost no plastic: This is the main cutting characteristics of hardened steel. When the hardness of hardened steel to HRC50 ~ 60, its strength up to σb = 2100 ~ 2600MPa, according to classification by processing material processing requirements, the hardness and strength of hardened steel are 9a-class, are the most difficult to cut materials.
(2) hardened steel cutting power, cutting temperatures are high: from the high hardness and high strength of the workpiece cut chips, the unit cutting force of up to 4500MPa. In order to improve the cutting conditions, increase heat dissipation area, the smaller the main tool selection and vice declination angle. At this time will cause vibration, required to have a good technology system rigidity.
(3) hardened steel is not easy to BUE: hardened steel, high hardness, brittleness, cutting is not easy to BUE, get a lower surface to be machined surface roughness.
(4) collapse easily broken blade, wear: Because of the brittleness of hardened steel, cutting short the chip and blade contacts, cutting force and cutting tool edge heat concentrated in the near collapse of broken blade easy to make and wear.
(5) Low thermal conductivity: the thermal conductivity is generally hardened steel is 7.12W / (m • K), about 45 steel, 1 / 7. Machinability of the material level is 9a-level, are difficult to cut materials. As low thermal conductivity of hardened steel, the cutting heat is difficult to pass chip away, cutting temperature is high, accelerated tool wear.
2. How to Select hardened steel cutting tool material?
Reasonable choice of cutting tool material is an important condition of hardened steel. According to the characteristics of hardened steel cutting tool materials not only have high hardness, wear resistance, heat resistance, and to have a certain strength and thermal conductivity.
(1) carbide: To improve the performance of cemented carbide, the choice of carbide, should give priority to adding the right amount of TaC or NbC carbide ultrafine particles. Because WC-Co cemented carbide in the class, adding TaC after the original can be improved high temperature strength of 800 ℃ 150 ~ 300MPa, room temperature hardness HV40 ~ 100. After adding NbC, high-temperature strength increased 150 ~ 300MPa, room temperature hardness HV70 ~ 150. And TaC and NbC grain refinement can improve the crater wear resistant carbide ability. TaC can also reduce the friction coefficient, lower cutting temperature, enhanced carbide thermal cracking and thermoplastic deformation capacity, but also the WC grain refinement to 0.5 ~ 1μm, the hardness HRA1.5 ~ 2, bending strength can increase 600 ~ 800MPa, high temperature hardness than carbide.
Used to cut hardened steel, carbide grades are: YM051, YM052, YN05, YN10, 600,610,726,758,767,813 and so on.
(2) hot pressing silicon nitride ceramics and ceramic composites: TiC added in Al2O3 and other metal elements and the use of hot pressing process, to improve the ceramic density, improve the performance of alumina-based ceramics, it's hardness to HRA95.5, bending strength can reach 800 ~ 1200MPa, heat resistance up to 1200 ℃ ~ 1300 ℃, can be used to reduce wear and diffusion bonding. Its main brands are AG2, AG3, AG4, LT35, LT55, AT6 and so on. Si3N4 silicon nitride based ceramics are adding TiC and other metal elements, and its hardness HRA93 ~ 94, the bending strength is 700 ~ 1100MPa. Its main brands are HS73, HS80, F85, ST4, TP4, SM, HDM1, HDM2, HDM3. Both ceramics for turning, milling, boring, planing hardened steel.
(3), cubic boron nitride composite film (PCBN) tool: its hardness HV8000 ~ 9000, composite flexural strength of 900 ~ 1300MPa, relatively high thermal conductivity, heat resistance to 1400 ℃ ~ 1500 ℃, the tool material the highest. It is very suitable for hardened steel, semi-finishing and finishing.
The best hardened steel cutting tool material is cubic boron nitride, followed by composite ceramics, and then followed by the new carbide grades.
3. How to choose the cutting tool geometry parameters of hardened steel?
When cutting hardened steel, having a good tool material, tool geometry without reasonable parameters, they can not achieve satisfactory results. Therefore, according to the specific tool material, workpiece material and cutting conditions, a reasonable choice of tool geometry, in order to effectively play the cutting tool material should have.
(1) front: cutting the size of the anterior horn of the great influence of hardened steel. Since the hardness of hardened steel, high strength, cutting power, and concentrated near the edge of the tool. In order to avoid chipping and playing knife, rake angle should be zero and negative selection, the general γ0 =- 10 ° ~ 0 °. Workpiece material hardness, intermittent cutting, should be selected large negative rake angle, γ0 =- 10 ° ~ -30 °. If you use positive rake angle indexable inserts should grind bγ = 0.5 ~ 1mm wide, γ01 =- 5 ° ~ -15 ° larger negative chamfering, to enhance the edge strength.
(2) horn: hardened steel cutting tools should be higher than normal posterior horn of the posterior horn of the large number of tools to reduce the friction flank, generally α0 = 8 ° ~ 10 ° as well.
(3) the main and sub-declination angle: the tip in order to enhance strength and improve heat dissipation, the main angle κr = 30 ° ~ 60 °, Vice-angle κ'r = 6 ° ~ 15 °.
(4) inclination: blade angle is negative, you can increase tip strength. But the negative is too large, will force Fp increases system rigidity is poor in the process, causing the vibration. So under normal circumstances, λs =- 5 ° ~ 0 °; intermittent cutting, λs =- 10 ° ~ -20 °; hardened hob scraper, it's blade angle λs =- 30 °.
(5) tip radius: it is the size of the impact of tip strength and machined surface roughness. Rigidity due to the impact of process systems, tip radius γε = 0.5 ~ 2mm appropriate.
Hardened steel cutting tools, in a reasonable, based on the selected geometric parameters must be carefully grinding and research Bei, the surface of the grinding tool to improve the quality of the tool life is improved.
4. How to choose when cutting hardened steel cutting?
Machining hardened steel cutting, mainly based tool material, physical and mechanical properties of workpiece material, workpiece shape, rigidity and allowance process system to choose. Three elements in the choice of cutting parameters, first consider selecting a reasonable cutting speed, followed by the depth of cut, and then followed by the feed.
(1) cutting speed: a general heat-resistant hardened steel at 200 ℃ ~ 600 ℃, while the carbide heat resistance of 800 ℃ ~ 1000 ℃, the heat resistance of ceramic tool 1100 ℃ ~ 1200 ℃, cubic nitrogen of the heat resistance of boron 1400 ℃ ~ 1500 ℃. In addition to high-speed steel, in general, hardened steel to about 400 ℃, its hardness began to decline, and the tool material remained its original hardness. So when cutting hardened steel, full use of the above this feature, select the cutting speed should not be too low or too high to maintain the tool has some durability. From the current experience, a different cutting tool materials, cutting hardened steel, carbide cutting tools Vc = 30 ~ 75m/min; ceramic tool Vc = 60 ~ 120m/min; cubic boron nitride cutting tools Vc = 100 ~ 200m / min. In intermittent cutting and workpiece material hardness is too high, should reduce the cutting speed, generally above the lowest cutting speed of about 1 / 2. The best in cutting speed continuous cutting, to cut the chip Chenganhongse appropriate.
(2) depth of cut: general allowance and process systems based on rigid selection, under normal circumstances, αp = 0.1 ~ 3mm.
(3) feed: generally 0.05 ~ 0.4mm / r. The workpiece material hardness or intermittent cutting, in order to reduce the unit cutting force, feed rate should be reduced to prevent chipping and play knife.
5. How hardened steel with a ceramic cutting tool?
Ceramic cutting tool material hardened steel, carbide cutting than hardened steel, has a significant effect. This was reflected in the hardness of ceramic cutting tools and heat resistance than carbide. Use it to create the turning, milling, thread cutting tools, can be successful in cutting hardened steel, its durability is higher than YT05, 643, YM052 carbide.
(1) full ceramic tool material carbide hardness and heat resistance than the high of this feature, select the cutting speed should be higher than the hardened steel cutting carbide cutting speed, generally 50% higher. If the cutting speed 50m/min, the ceramic tool flank wear and carbide close. When cutting speed increased to 95m/min, its wear resistance is much higher than YT05 carbide. Such as the use made of ceramic blade cutter blade on three sides, the cutting speed to 102m/min end milling depth 5.2mm, width 16mm, length 700mm hardened steel keyway, the tool is basically no wear.
(2) ceramic tool in cutting under impact load, the tool should be selected small main angle, or use a large circular arc blade tip to increase tip strength, to avoid tool damage. If using a circular blade made of ceramic machine clip end milling cutter, milling hardened steel, Vc = 120 ~ 150m/min, Vf = 230 ~ 290mm/min, αp = 1 ~ 2mm.
(3) should be negative with negative rake angle and blade angle, in order to facilitate and increase the blade tip strength. Blade and flank roughness Ra is less than 0.4μm.
(4) cutting without cutting fluid generally, to use, throughout the full supply to, or blade cracks due to thermal expansion and contraction.
(5) lower than the bending strength of ceramic cutting tools carbide bending strength, in order to reduce the force per unit area of the tool, cutting feed rate to be smaller, typically f = 0.08 ~ 0.15mm / r.
6. How to use cubic boron nitride cutting tool hardened steel?
Cubic boron nitride cutting tools (CBN) is not only a good material for manufacture of abrasives and grinding it easy (free diamond grinding wheel) is used to make turning tools, boring tools, milling cutters, gun drill, reamer, gear tools such good material. CBN cutting of hardened steel is mainly used, can also be used to cut other difficult to cut materials. It not only has a high metal removal rate, and have a good surface quality. Cutting of hardened steel can be effectively replaced by grinding to reduce the manufacturing processes and improve productivity. Sold on the market of CBN inserts, mostly in the composite film with the form of carbide, indexable inserts made of or tool, its purpose is to increase the flexural strength of CBN inserts.
Because CBN tools, high hardness (HV8000 ~ 9000), high heat resistance (1400 ℃ ~ 1500 ℃), when used several times to allow the cutting speed is higher than the carbide cutting hardened steel, and durability is the hardness of alloy several times to several times. CBN tools when cutting hardened steel and carbide tools compared.
CBN tools suitable for low speed cutting, CBN cutting tool by cutting heat generated in the cutting area within a small softening of workpiece material to cutting.
In the cutting hardness of HRC55 ~ 65 of the material, CBN tool cutting speed should be 50 ~ 120m/min. Milling of the Vc = 100 ~ 160m/min, feed rate per minute, Vf = 70 ~ 160mm/min; reaming when Vc = 60 ~ 130m/min, ap = 0.1 ~ 0.2mm, f = 0.07 ~ 0.2mm / r . CBN tool is mainly used for hardening steel, semi-finishing and finishing. The machined surface is not generated as grinding burns, as the phenomenon is about ten times more efficient than grinding.
How to buy engraving machine?
How to buy engraving machine?
First, choose wood engraving machine - see the engraving machine format size.
Customers should be based on business needs and financial situation, to choose their own engraving machine the size of the model and its power. General small-format engraving machine with 600mm × 600mm and 600mm × 900mm, the width of the feed is 700mm. Small-format two-color board engraving engraving machine is the most basic application, acceptance is very good. Then smaller engraving machine with almost the same price, but the engraving plate color when the Conference Board, more cumbersome and unnecessary waste. Large format engraving machine has 1200mm × 1200mm, 200mm × 1500mm, 1500mm × 2400mm, 2400mm × 3000mm, more models into the Division engraving machine width more than 1350mm, now available in plexiglass and PVC plate sizes are 1300mm × 2400mm, so that several models of the demand for large format engraving machine more suitable for the customer.
Second, buy engraving machine - note engraving machine spindle motor.
Computer engraving machine spindle motor is an important component parts, the performance of the overall performance of computer engraving machine has a critical influence. Machining spindle is usually divided into two categories: precision machining high-power cutting spindle and the spindle.
1, precision machining spindle is characterized by low noise, high speed, height, particularly suitable for fine machining of the workpiece, such as seals, nameplates, badges, gifts and so on. Such motors are usually for high-speed frequency conversion motor, less power, like the 250W or less. The disadvantage is the ability to cut thick materials poor, are not cut thicker materials. Flange ball valve
2, power off the spindle, is mainly used for cutting, high-power moment, characterized by power, cutting ability, especially for cut-yu, the three-dimensional characters, of course, you can create badges, nameplates, seals and so on. Such high-power spindle motor according to the characteristics of the frequency can be divided into high-speed brushless AC motor and AC motor brushes, the main difference is: A, high-speed brushless frequency conversion motor, variable speed range from 70,060,000 rev / min, and generally have brush AC motor does not exceed the maximum speed 24000 rev / min: B, high precision brushless frequency conversion motor rotation, wear, low noise, make noise, much lower than the brush AC motor; C, brushless frequency conversion motor stall characteristics, and because There are special inverter circuit current limit, short of burning the motor will not stall, and brush the exchange machine overload or stall smoke when burned quickly, and not repairable; D, brushless frequency conversion motor the use of variable frequency speed control technology, is a professional grade products, long life, 1 year free replacement provided by the manufacturer, after the high-speed bearings can also be replaced to maintain the motor, and AC motor brush life is about the use of electric Sapporo 300 hours brushless motor or the motor must be replaced, so the brushless AC motor is not typical day warranty.
Third, the engraving machine and speed control options: control can now be divided into three types:
A, all the computing work done with computer control, computer engraving machine at work is in working condition, can not be other layout work, this may be caused by solid waste computer misuse.
B, single-chip computer control, the controller can work at the same time carving machine layout, but can not turn off the computer, which in fact is equivalent to savings of 7 on a computer, computer misuse and reduce the waste caused.
C, using USB port to transfer data, the system has more than 32M of memory. Just save the finished file, you can immediately completely out of the computer, turn off the computer or other typesetting. This approach greatly improves the efficiency of engraving machine.
Fourth, we must pay attention to the rail. Large engraving machine must be imported using the square rails widen, load capacity and accuracy to maintain its ability to round rail for more than 30 times to ensure high-quality high-speed engraving machine.
Fifth, consider the problem of precision engraving machine, engraving machine 1mm small-format character, or large format engraving machine engraved 1.5mm small print, under a magnifying glass to be seen very clearly.
First, choose wood engraving machine - see the engraving machine format size.
Customers should be based on business needs and financial situation, to choose their own engraving machine the size of the model and its power. General small-format engraving machine with 600mm × 600mm and 600mm × 900mm, the width of the feed is 700mm. Small-format two-color board engraving engraving machine is the most basic application, acceptance is very good. Then smaller engraving machine with almost the same price, but the engraving plate color when the Conference Board, more cumbersome and unnecessary waste. Large format engraving machine has 1200mm × 1200mm, 200mm × 1500mm, 1500mm × 2400mm, 2400mm × 3000mm, more models into the Division engraving machine width more than 1350mm, now available in plexiglass and PVC plate sizes are 1300mm × 2400mm, so that several models of the demand for large format engraving machine more suitable for the customer.
Second, buy engraving machine - note engraving machine spindle motor.
Computer engraving machine spindle motor is an important component parts, the performance of the overall performance of computer engraving machine has a critical influence. Machining spindle is usually divided into two categories: precision machining high-power cutting spindle and the spindle.
1, precision machining spindle is characterized by low noise, high speed, height, particularly suitable for fine machining of the workpiece, such as seals, nameplates, badges, gifts and so on. Such motors are usually for high-speed frequency conversion motor, less power, like the 250W or less. The disadvantage is the ability to cut thick materials poor, are not cut thicker materials. Flange ball valve
2, power off the spindle, is mainly used for cutting, high-power moment, characterized by power, cutting ability, especially for cut-yu, the three-dimensional characters, of course, you can create badges, nameplates, seals and so on. Such high-power spindle motor according to the characteristics of the frequency can be divided into high-speed brushless AC motor and AC motor brushes, the main difference is: A, high-speed brushless frequency conversion motor, variable speed range from 70,060,000 rev / min, and generally have brush AC motor does not exceed the maximum speed 24000 rev / min: B, high precision brushless frequency conversion motor rotation, wear, low noise, make noise, much lower than the brush AC motor; C, brushless frequency conversion motor stall characteristics, and because There are special inverter circuit current limit, short of burning the motor will not stall, and brush the exchange machine overload or stall smoke when burned quickly, and not repairable; D, brushless frequency conversion motor the use of variable frequency speed control technology, is a professional grade products, long life, 1 year free replacement provided by the manufacturer, after the high-speed bearings can also be replaced to maintain the motor, and AC motor brush life is about the use of electric Sapporo 300 hours brushless motor or the motor must be replaced, so the brushless AC motor is not typical day warranty.
Third, the engraving machine and speed control options: control can now be divided into three types:
A, all the computing work done with computer control, computer engraving machine at work is in working condition, can not be other layout work, this may be caused by solid waste computer misuse.
B, single-chip computer control, the controller can work at the same time carving machine layout, but can not turn off the computer, which in fact is equivalent to savings of 7 on a computer, computer misuse and reduce the waste caused.
C, using USB port to transfer data, the system has more than 32M of memory. Just save the finished file, you can immediately completely out of the computer, turn off the computer or other typesetting. This approach greatly improves the efficiency of engraving machine.
Fourth, we must pay attention to the rail. Large engraving machine must be imported using the square rails widen, load capacity and accuracy to maintain its ability to round rail for more than 30 times to ensure high-quality high-speed engraving machine.
Fifth, consider the problem of precision engraving machine, engraving machine 1mm small-format character, or large format engraving machine engraved 1.5mm small print, under a magnifying glass to be seen very clearly.
How to buy CNC drilling machine drill
How to buy CNC drilling machine drill?
CNC drilling machine drill bit selection methods:
1, CNC drilling machine drill bit types and characteristics:
PCB drilling with straight shank twist drill bits, twist drill head fixed handle and fixed handle spade (undercut) drill bit. Straight Shank Twist Drill head mostly for single-head drilling machine, drilling of printed circuit board or a simple single panel, now in large circuit board production plant has been rarely seen, the drilling depth of up to 10 times the drill diameter. Laminated substrate is not high in the case of drilling with drill sleeve to avoid bias. At present, most manufacturers use CNC drilling machine, CNC drilling machine using a fixed shank carbide drill bit, the feature is to automatically replace the drill bit. High positioning accuracy, do not use the drill sleeve. Large helix angle, chip speed, suitable for high-speed cutting. Flutes range in length, is an inverted cone drill diameter, drill hole wall friction with the small, high quality drilling. Common drill shank diameter 3.00mm and 3.175mm.
2, CNC drilling machine drill material:
PCB drilling with carbide drill bits are generally used as epoxy glass fabric copper plate for re-tool wear particularly fast. Carbide is tungsten carbide powder as the so-called matrix, cobalt powder as binder by the pressure, sintering. Usually 94% WC, 6% cobalt. Because of its high hardness, very wearable, there is a certain strength, suitable for high-speed cutting. But toughness is poor, very brittle, in order to improve the performance of cemented carbide, and some carbon substrate used in chemical vapor deposition of a layer of 5 to 7 microns special hard titanium carbide (TIC) or titanium nitride (TIN), it has a higher hardness. Some ion implantation technology, titanium, nitrogen, and carbon into the depth of its base must not only improve the hardness and strength, and regrinding the drill bit into the ingredients when they can move into. Some physical methods used to generate the bit at the top of a layer of diamond film, which greatly improves the hardness and wear resistance of drill. Carbide hardness and strength, not only with the ratio of tungsten carbide and cobalt, but also with the powder particles. Ultra-fine particles of solid carbide drills, the tungsten carbide phase, the average grain size of 1 micron or less. This drill is not only high hardness and compressive and flexural strength are improved. In order to save costs now handle many bits are welded structure, the original carbide drill bit as a whole are now drilling the rear handle with a stainless steel, greatly reduced the cost of different materials but due to its dynamic concentricity less than the overall hard alloy drill, especially in small-diameter side.
CNC drilling machine drill bit selection methods:
1, CNC drilling machine drill bit types and characteristics:
PCB drilling with straight shank twist drill bits, twist drill head fixed handle and fixed handle spade (undercut) drill bit. Straight Shank Twist Drill head mostly for single-head drilling machine, drilling of printed circuit board or a simple single panel, now in large circuit board production plant has been rarely seen, the drilling depth of up to 10 times the drill diameter. Laminated substrate is not high in the case of drilling with drill sleeve to avoid bias. At present, most manufacturers use CNC drilling machine, CNC drilling machine using a fixed shank carbide drill bit, the feature is to automatically replace the drill bit. High positioning accuracy, do not use the drill sleeve. Large helix angle, chip speed, suitable for high-speed cutting. Flutes range in length, is an inverted cone drill diameter, drill hole wall friction with the small, high quality drilling. Common drill shank diameter 3.00mm and 3.175mm.
2, CNC drilling machine drill material:
PCB drilling with carbide drill bits are generally used as epoxy glass fabric copper plate for re-tool wear particularly fast. Carbide is tungsten carbide powder as the so-called matrix, cobalt powder as binder by the pressure, sintering. Usually 94% WC, 6% cobalt. Because of its high hardness, very wearable, there is a certain strength, suitable for high-speed cutting. But toughness is poor, very brittle, in order to improve the performance of cemented carbide, and some carbon substrate used in chemical vapor deposition of a layer of 5 to 7 microns special hard titanium carbide (TIC) or titanium nitride (TIN), it has a higher hardness. Some ion implantation technology, titanium, nitrogen, and carbon into the depth of its base must not only improve the hardness and strength, and regrinding the drill bit into the ingredients when they can move into. Some physical methods used to generate the bit at the top of a layer of diamond film, which greatly improves the hardness and wear resistance of drill. Carbide hardness and strength, not only with the ratio of tungsten carbide and cobalt, but also with the powder particles. Ultra-fine particles of solid carbide drills, the tungsten carbide phase, the average grain size of 1 micron or less. This drill is not only high hardness and compressive and flexural strength are improved. In order to save costs now handle many bits are welded structure, the original carbide drill bit as a whole are now drilling the rear handle with a stainless steel, greatly reduced the cost of different materials but due to its dynamic concentricity less than the overall hard alloy drill, especially in small-diameter side.
Tuesday, January 3, 2012
How to use Reaper
Reaper-How to use Reaper?
Reaper machines in use before the instructions should be required to conduct a comprehensive inspection, including:
(1) food inspection seal does not leak. Taiwan and the inclination of the cutting and threshing part of the burglary to feed the tape at the bar, the lower grain pushing device, re-off device, pushing the bottom and the elevator control device of the manhole covers activities such as joints, must be leakproof seal food inspection and testing.
(2) Check the Reaper machine threshing gap. First, check the blade is intact, blade selection is solid, the blade gap, the gap is suitable compression edge device, then check the size and threshing gap uniformity to meet the requirements.
(3) Check the Reaper machine transmission parts. Check for bent main shaft, bearing clearance, shaft and bearing fixed, the rotation of the shaft. Then open to the engine rated speed, check the threshing drum speed (900-1000 rev / min), fan speed (700-800 rev / min), does not meet the speed requirements of the harvester to adjust.
(4) Check the Reaper machine accessories. Clutch of standard technical condition should not slip up after bonding power, transmission power, reliable, complete separation of power, shift light, no fight tooth phenomenon. Check the high speed of the sprocket, belt wheel, bearing on the top wire of solid situation. Also check the relative position of each component is correct. In particular, check the chain tension and tape should be consistent with the model.
Reaper machines in use before the instructions should be required to conduct a comprehensive inspection, including:
(1) food inspection seal does not leak. Taiwan and the inclination of the cutting and threshing part of the burglary to feed the tape at the bar, the lower grain pushing device, re-off device, pushing the bottom and the elevator control device of the manhole covers activities such as joints, must be leakproof seal food inspection and testing.
(2) Check the Reaper machine threshing gap. First, check the blade is intact, blade selection is solid, the blade gap, the gap is suitable compression edge device, then check the size and threshing gap uniformity to meet the requirements.
(3) Check the Reaper machine transmission parts. Check for bent main shaft, bearing clearance, shaft and bearing fixed, the rotation of the shaft. Then open to the engine rated speed, check the threshing drum speed (900-1000 rev / min), fan speed (700-800 rev / min), does not meet the speed requirements of the harvester to adjust.
(4) Check the Reaper machine accessories. Clutch of standard technical condition should not slip up after bonding power, transmission power, reliable, complete separation of power, shift light, no fight tooth phenomenon. Check the high speed of the sprocket, belt wheel, bearing on the top wire of solid situation. Also check the relative position of each component is correct. In particular, check the chain tension and tape should be consistent with the model.
Cubic boron nitride cutting tools
Cubic boron nitride tool type and use:
Cubic boron nitride cutting tools in the past mainly for finishing, the last decade by improving the production process, raw material purity and grain size control, the use of composite materials and other hot-pressing process, the significant improvement of its brittleness, toughness, the use of reliable greatly improved as a routine tool has been applied in production, to improve efficiency, ensure product quality plays an important role.
Cubic boron nitride cutting tools to develop new trends:Cubic boron nitride cutting tool is an advanced tool, a bright future. Semi-finishing and finishing first in time, in some cases even roughing operations, with its hardened steel, chilled cast iron, 35HRC or more of cobalt and nickel-based superalloys and other difficult materials is also effective . For example, the Russian T-10 (PCBN) inserts with good impact resistance, it can be used semi-finishing and finishing, can also be used to eat back cutter roughing capacity of 6mm. Cubic boron nitride is currently the world's annual consumption of about 10% to 15% growth rate.Synthetic superhard cubic boron nitride cutting tool materials, the present single crystal of the coarse particles, high-intensity, multi-direction. Japanese production of single crystals of inorganic materials CBN diameter of 3mm. De Beers produced PCBN products, maximum diameter of 101.6mm, and then laser cut into any shape required, the high hardness materials can be processed 70HRC.Cubic boron nitride cutting tool materials more expensive, in order to expand its scope of application, has been developed abroad, price is relatively low compared with the cubic boron nitride coated tools. It is the use of chemical vapor deposition (CVD) in general-purpose tungsten-cobalt (K) type carbide substrate (in principle, can be coated in any base body) coated with a thin layer of cubic boron nitride superhard materials. Britain has also developed a PCBN inserts on the coating layer with a CVD method nickel, copper, titanium, chromium, tantalum, cobalt compounds, as well as TiN or TiC protective coating, high wear resistance than ordinary PCBN inserts 3 times. Lellond by the company developed a ceramic and CBN superhard composite materials, which combines the advantages of these two materials, high-speed machining is ideal for hard wear-resistant cast iron materials.Cubic boron nitride cutting tools depends on the widespread use of high-speed, high rigidity, high vibration resistance of the metal cutting machine tools, and new varieties of high-strength grades of blades, depending on processing conditions and should select the appropriate cutting parameters to be processed with material phase "matching." The current development of cubic boron nitride cutting tools, on the one hand to try to improve the quality of the blade to reduce blade costs; the other hand, further developed the finer grain size materials to increase their density, reducing the edge serrated edge, so that it can edge worn more sharp, but to solve the cubic boron nitride tool sharpening to improve the efficiency and quality.
Cubic boron nitride cutting tool materials, performance characteristics
Cubic boron nitride cutting tools is the use of cubic boron nitride (CBN) made some cutting tool. Cubic boron nitride (CBN) is a boron nitride BN isomers of the same elements, with the diamond structure is similar to ultra-high temperature high pressure technology with synthetic superhard materials. Its hardness only to diamond (hardness up to 8000 ~ 9000HV), and high thermal stability (up to 1250 ~ 1350 ℃), chemical inertness of the iron group elements, anti-bonding ability, you can use the diamond grinding wheel the blade, so for more than 35HRC machining hard materials, such as a variety of hardened steel (carbon tool steel, alloy tool steel, high-speed steel, bearing steel, tool steel, etc.), chilled cast iron, cobalt and nickel base high-temperature alloys, tungsten carbide, surface coating (solder) materials and high hard wear-resistant materials can also be used for titanium alloys, pure nickel, pure tungsten and other materials processing. It is a car, instead of grinding mill one of the best tools. Cubic boron nitride cutting tools with hardened steel surface roughness Ra1.60.4μm, accuracy up to IT7IT6. Figure 1 shows the hard turning with CBN cutting tools tungsten alloy case.
Cubic boron nitride cutting tools have limitations on the use, as it more brittle, less strength and toughness, not to break under shock loading surface processing. In addition, it processed the iron group elements of soft materials, because of easy to produce long chips, scratches, tool rake face and the formation of BUE, cutting force fluctuations will lead to damage to the tool.In order to improve the impact resistance of boron nitride cutting tools, has developed a class of graphite, hexagonal boron nitride with (g-BN or h-BN) as raw material, explosive synthesis of a new type of WBN material (WBN is an lead-zinc structure BN). It has a very high toughness and sintering activity, easily transformed into CBN, and easy and CBN sintered together into a strength and hardness close to the level of poly-CBN crystals.WBN and two-phase sintered CBN is used to make up for the toughness of CBN WBN brittle, its impact strength than pure CBN sintered body by 60%, an increase of 2.53 times the fracture toughness, resistance to flexural strength increased by 1 times, anti- compressive strength and carbide considerable thermal stability for the 1100 ~ 1200 ℃. Can be used to break the surface of the workpiece processing, such as gear tooth surface, welding the workpiece surface or a groove.Currently, WBN and two-phase sintered CBN tools in the U.S., Japan and Russia and other countries in the automotive industry wide application, such as for processing link, quite cylinder, cylinder liners, brake wheel, crankshaft, flywheel, the types of pump shell-type parts of the car, boring and milling processes.1 type of cubic boron nitride cutting toolsAt present the production of cubic boron nitride cutting tools commonly used in three ways: overall polycrystalline cubic boron nitride (PCBN) cutting tools, polycrystalline cubic boron nitride and carbide composite blade (PCBN / CC) and plated cubic boron nitride cutting tools . Among them, two types of tool use most.PCBN at high temperatures, high pressure, the number of polycrystalline CBN single crystals into polycrystalline material powder is sintered CBN crystal powder. PCBN / CC is in the strength and toughness of cemented carbide substrate, sintered or pressed 0.5 ~ 1mm thick layer made of a composite blade PCBN, it solves the cubic boron nitride blade bending strength and low inlay welding difficult issues. PCBN / CC welding or machine clip free way of making knives. For example, U.S. GE (General Electric) produced BZN blade, Russia's Toma-10 blade, the Japanese company Sumitomo Electric BN blades, as well as China's production of LDP-J-CF, DLS-F, LF, and LBN-Y-type series PCBN inserts are composite blades.Electroplated cubic boron nitride cutting tools is buried in sand plating method to nickel, copper and cobalt as binder, the CBN package inserts of fine particles in a certain size and geometry of the base surface of the tool surface, through the appropriate grinding is made. Zhengzhou Institute of abrasives grinding CBN plating production is such a reamer tool. Figure 2 - Figure 4 shows the production of several commonly used cubic boron nitride cutting tools.
Cubic boron nitride cutting tools in the past mainly for finishing, the last decade by improving the production process, raw material purity and grain size control, the use of composite materials and other hot-pressing process, the significant improvement of its brittleness, toughness, the use of reliable greatly improved as a routine tool has been applied in production, to improve efficiency, ensure product quality plays an important role.
Cubic boron nitride cutting tools to develop new trends:Cubic boron nitride cutting tool is an advanced tool, a bright future. Semi-finishing and finishing first in time, in some cases even roughing operations, with its hardened steel, chilled cast iron, 35HRC or more of cobalt and nickel-based superalloys and other difficult materials is also effective . For example, the Russian T-10 (PCBN) inserts with good impact resistance, it can be used semi-finishing and finishing, can also be used to eat back cutter roughing capacity of 6mm. Cubic boron nitride is currently the world's annual consumption of about 10% to 15% growth rate.Synthetic superhard cubic boron nitride cutting tool materials, the present single crystal of the coarse particles, high-intensity, multi-direction. Japanese production of single crystals of inorganic materials CBN diameter of 3mm. De Beers produced PCBN products, maximum diameter of 101.6mm, and then laser cut into any shape required, the high hardness materials can be processed 70HRC.Cubic boron nitride cutting tool materials more expensive, in order to expand its scope of application, has been developed abroad, price is relatively low compared with the cubic boron nitride coated tools. It is the use of chemical vapor deposition (CVD) in general-purpose tungsten-cobalt (K) type carbide substrate (in principle, can be coated in any base body) coated with a thin layer of cubic boron nitride superhard materials. Britain has also developed a PCBN inserts on the coating layer with a CVD method nickel, copper, titanium, chromium, tantalum, cobalt compounds, as well as TiN or TiC protective coating, high wear resistance than ordinary PCBN inserts 3 times. Lellond by the company developed a ceramic and CBN superhard composite materials, which combines the advantages of these two materials, high-speed machining is ideal for hard wear-resistant cast iron materials.Cubic boron nitride cutting tools depends on the widespread use of high-speed, high rigidity, high vibration resistance of the metal cutting machine tools, and new varieties of high-strength grades of blades, depending on processing conditions and should select the appropriate cutting parameters to be processed with material phase "matching." The current development of cubic boron nitride cutting tools, on the one hand to try to improve the quality of the blade to reduce blade costs; the other hand, further developed the finer grain size materials to increase their density, reducing the edge serrated edge, so that it can edge worn more sharp, but to solve the cubic boron nitride tool sharpening to improve the efficiency and quality.
Cubic boron nitride cutting tool materials, performance characteristics
Cubic boron nitride cutting tools is the use of cubic boron nitride (CBN) made some cutting tool. Cubic boron nitride (CBN) is a boron nitride BN isomers of the same elements, with the diamond structure is similar to ultra-high temperature high pressure technology with synthetic superhard materials. Its hardness only to diamond (hardness up to 8000 ~ 9000HV), and high thermal stability (up to 1250 ~ 1350 ℃), chemical inertness of the iron group elements, anti-bonding ability, you can use the diamond grinding wheel the blade, so for more than 35HRC machining hard materials, such as a variety of hardened steel (carbon tool steel, alloy tool steel, high-speed steel, bearing steel, tool steel, etc.), chilled cast iron, cobalt and nickel base high-temperature alloys, tungsten carbide, surface coating (solder) materials and high hard wear-resistant materials can also be used for titanium alloys, pure nickel, pure tungsten and other materials processing. It is a car, instead of grinding mill one of the best tools. Cubic boron nitride cutting tools with hardened steel surface roughness Ra1.60.4μm, accuracy up to IT7IT6. Figure 1 shows the hard turning with CBN cutting tools tungsten alloy case.
Cubic boron nitride cutting tools have limitations on the use, as it more brittle, less strength and toughness, not to break under shock loading surface processing. In addition, it processed the iron group elements of soft materials, because of easy to produce long chips, scratches, tool rake face and the formation of BUE, cutting force fluctuations will lead to damage to the tool.In order to improve the impact resistance of boron nitride cutting tools, has developed a class of graphite, hexagonal boron nitride with (g-BN or h-BN) as raw material, explosive synthesis of a new type of WBN material (WBN is an lead-zinc structure BN). It has a very high toughness and sintering activity, easily transformed into CBN, and easy and CBN sintered together into a strength and hardness close to the level of poly-CBN crystals.WBN and two-phase sintered CBN is used to make up for the toughness of CBN WBN brittle, its impact strength than pure CBN sintered body by 60%, an increase of 2.53 times the fracture toughness, resistance to flexural strength increased by 1 times, anti- compressive strength and carbide considerable thermal stability for the 1100 ~ 1200 ℃. Can be used to break the surface of the workpiece processing, such as gear tooth surface, welding the workpiece surface or a groove.Currently, WBN and two-phase sintered CBN tools in the U.S., Japan and Russia and other countries in the automotive industry wide application, such as for processing link, quite cylinder, cylinder liners, brake wheel, crankshaft, flywheel, the types of pump shell-type parts of the car, boring and milling processes.1 type of cubic boron nitride cutting toolsAt present the production of cubic boron nitride cutting tools commonly used in three ways: overall polycrystalline cubic boron nitride (PCBN) cutting tools, polycrystalline cubic boron nitride and carbide composite blade (PCBN / CC) and plated cubic boron nitride cutting tools . Among them, two types of tool use most.PCBN at high temperatures, high pressure, the number of polycrystalline CBN single crystals into polycrystalline material powder is sintered CBN crystal powder. PCBN / CC is in the strength and toughness of cemented carbide substrate, sintered or pressed 0.5 ~ 1mm thick layer made of a composite blade PCBN, it solves the cubic boron nitride blade bending strength and low inlay welding difficult issues. PCBN / CC welding or machine clip free way of making knives. For example, U.S. GE (General Electric) produced BZN blade, Russia's Toma-10 blade, the Japanese company Sumitomo Electric BN blades, as well as China's production of LDP-J-CF, DLS-F, LF, and LBN-Y-type series PCBN inserts are composite blades.Electroplated cubic boron nitride cutting tools is buried in sand plating method to nickel, copper and cobalt as binder, the CBN package inserts of fine particles in a certain size and geometry of the base surface of the tool surface, through the appropriate grinding is made. Zhengzhou Institute of abrasives grinding CBN plating production is such a reamer tool. Figure 2 - Figure 4 shows the production of several commonly used cubic boron nitride cutting tools.
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