Applications of PCBN tools

1. Suitable for high-speed and ultra-high-speed cutting technology

PCBN tool is most suitable for high speed cutting of cast iron, hardened steel and other materials. It can be seen from the relationship between the wear of the PCBN tool and the cutting distance when cutting cast iron and hardened steel: when the cutting speed exceeds a certain limit, the higher the cutting speed, the lower the wear speed of the PCBN tool, that is, the tool life under high speed cutting is higher, this characteristic is especially suitable for modern high speed cutting.

2. Hard cutting technology of the best tool material

Finishing of quenching hardware (hardness above HRC55), usually by grinding method to finish, but with the development of cutting tool materials and lathe (especially CNC lathe) the improvement of the machining accuracy, replace the grinding with hard cutting to complete parts processing has become a new finishing way, eventually this car for grinding process method has the following:

Advantages:

(1) It can improve machining flexibility and break through the limitation of grinding wheel. Workpiece with different geometric shapes can be machined by changing the cutting edge and cutting mode.

(2) The environmental protection problem in cutting is increasingly serious, the waste liquid and waste generated by grinding is more and more difficult to deal with and remove, and harmful to human body, and the hard cutting does not need to add coolant, which is of great significance.

(3) High cutting efficiency, short processing time, small equipment investment cost, can reduce the processing cost.

(4) The energy consumed by cutting the same volume is only 20% of that consumed by grinding, so the cutting heat generated is less, the machined surface is not easy to cause burns and small cracks, and it is easy to maintain the integrity of the surface performance of the workpiece.

(5) Under the same metal removal rate, hard cutting saves energy compared with grinding.

Usually used for hard cutting tool materials are ceramic, TiC coated blade and PCBN tool materials, but to carry out hard turning at a higher speed (more than 1000m/min), PCBN is the best tool material variety. For example, in the automobile transmission synchronous sleeve fork (material 20CrMnTi, hardness HRC58-62) processing by car instead of grinding, the efficiency is increased more than 4 times, the processing cost is reduced to the original grinding process 1/3 ~ 1/2.

3. Ideal tool material for dry cutting process

Due to economic and environmental reasons, dry cutting has become an important research topic in the field of machinery manufacturing in recent years. Let's first look at the problems caused by the use of cutting fluid in wet cutting process:

(1) Long-term exposure to the air or cutting heat caused by cutting fluid mist volatiles, easy to pollute the environment, harm the health of the operator, cutting fluid sulfur, chlorine and other additives harm more, affect the quality of processing surface.

(2) the use of cutting fluid affects the processing cost, according to statistics, cutting fluid accounted for 15% of the production cost, while the tool cost only accounted for 3% ~ 4%.

(3) The leakage and overflow of cutting fluid will pollute the environment and easily cause safety and quality accidents.

(4) Cutting fluid transmission, recovery, filtration and other devices and their maintenance costs are high, increasing production costs.

Due to the above reasons, dry cutting technology has been applied in western industrial developed countries. The "Red Crescent" dry cutting process, recommended by Makino, maximized the cutting performance of the tool and increased productivity compared to wet cutting. Its mechanism is because the cutting speed is very high, the heat generated in the front of the tool, so that the cutting area near the material to achieve red hot state, yield strength decline, and then achieve the effect of improving the cutting efficiency. The premise of the red crescent dry cutting process is that at a higher cutting temperature, the strength of the material to be cut has significantly decreased, become easy to cut, and the strength of the tool material in the same state to have better red hardness and thermal stability, but also have better wear resistance and anti-bonding.

Suitable for dry cutting process tool materials are ceramic, cermet, coated carbide and PCBN tool materials, but in terms of red hardness and thermal stability, PCBN material is the most suitable for dry cutting process tool materials, and because of the PCBN tool material has the advantages of the above, more suitable for high-speed dry cutting conditions, The comparison between dry cutting and wet cutting of gray cast iron with PCBN tool shows that PCBN has a higher tool life than wet cutting under high speed dry cutting.

4. Suitable for automatic processing and difficult processing materials processing

PCBN cutter has high hardness and wear resistance, and can process high-precision parts (small size dispersion) for a long time under high cutting speed, which greatly reduces the number of tool changes and the time spent in tool wear compensation downtime. Therefore, it is very suitable for CNC machine tools and processing equipment with a high degree of automation, and can give full play to the efficiency of the equipment.

In the application of difficult to process materials, PCBN tool also shows its excellent performance, such as surface spray welding (coating) material processing, with other materials of tool processing, tool life is very low, also cannot use grinding method processing, and PCBN is the only suitable tool material. For example, the high alloy wear-resistant cast iron used in petroleum power station equipment, using PCBN tool than carbide tool to improve the cutting efficiency of more than 4 times, the cost of a single tool is reduced to the original 1/5. In addition, the PCBN tool also shows good cutting performance in the machining of cemented carbide and other sintered materials.

Additional: PCBN tool application examples

Because of PCBN has high hardness and wear resistance, do not react with iron group metals at high temperature of chemical inertness, so it is mainly used for high hardness material and machining of difficult-to-machine materials, such as hardened steel, high alloy wear resistant cast iron, high temperature alloy, high speed steel, surface spray welding materials, sintered metal materials machining difficult-to-machine materials.

(1) When machining hardened steel, the effect of turning instead of grinding can be played. Because the cutting depth is more than ten times larger than the grinding depth, the machining efficiency is high and the surface is not burned. For example, the machining efficiency of variable speed sliding gear (20CrMnTi, hardness HRC58 ~ 62) by turning instead of grinding is more than 4 times higher than that of original grinding.

(2) Machining wear-resistant cast iron with high alloy (containing tungsten or chromium 18%), the cutting speed is more than 10 times higher than the hard alloy tool, and the cutting efficiency is more than 4 times higher.

(3) Processing of high cobalt chromium molybdenum corrosion and heat resistant alloy, PCBN cutting speed of 160m/min, is 8 times the carbide tool.

(4) Processing thermal spraying (spray welding) materials, surface spray welding parts cannot be processed by grinding, and the cutting efficiency of the carbide tool is very low, using the PCBN tool can improve the processing efficiency, saving more than 50% of the processing cost. PCBN tool can also be used for non-ferrous metal precision cutting and sintered metal cutting and so on.

---EDITOR: Lexi Pang

---POST: Doris Hu