Which CNC brand of turning tools are suitable for high-speed machining

PCBN tools are most suitable for high-speed cutting of materials such as cast iron and hardened steel. When cutting cast iron and hardened steel with PCBN tools, the relationship between tool flank wear and cutting distance can be seen: when the cutting speed exceeds a certain limit, the higher the cutting speed, the lower the PCBN tool flank wear speed, that is, high speed On the contrary, the tool life under cutting is high, this feature is especially suitable for modern high-speed cutting processing.

The best tool material for hard cutting technology

The finishing of hardened hardware (hardness above HRC55) is usually done by grinding. However, with the development of tool materials and the improvement of machining accuracy of lathes (especially CNC lathes), hard cutting is used instead of grinding. To complete the final processing of the parts has become a new way of finishing. This method of turning instead of grinding has the following advantages:

(1) It can improve the processing flexibility, break through the limitation of grinding wheel grinding, and can process workpieces with different geometric shapes by changing the cutting edge and the way of cutting;

(2) The environmental protection problem in cutting is becoming more and more serious. The waste liquid and waste produced by grinding are more and more difficult to handle and remove, and they are harmful to the human body. Hard cutting does not require coolant, which is of great significance;

(3) The cutting efficiency is high, the processing time is short, the equipment investment cost is small, and the processing cost can be reduced;

(4) The energy consumed by cutting the same volume is only 20% of grinding, so the cutting heat is less, the machined surface is not easy to cause burns and micro 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.

The tool materials usually used for hard cutting include ceramics, TiC coated inserts and PCBN tool materials, but hard turning is required at a higher speed (above 1000m/min), PCBN is the best tool material variety. For example, when the shift fork (material 20CrMnTi, hardness HRC58～62) of the automobile gearbox synchronizer sleeve is processed by car instead of grinding, the efficiency is increased by more than 4 times, and the processing cost is reduced to 1/3～1/ of the original grinding process. 2.

Ideal tool material for dry cutting process

Due to economic and environmental reasons, dry cutting processing methods have become a key 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 the wet cutting process:

(1) Long-term exposure to the air or cutting fluid mist-like volatilization caused by cutting heat during cutting can easily pollute the environment and endanger the health of the operator. Additives such as sulfur and chlorine in the cutting fluid are more harmful and affect processing. Surface Quality;

(2) The use of cutting fluid affects processing costs. According to statistics, cutting fluid accounts for 15% of production costs, while tool costs only account for 3% to 4%;

(3) Leakage and overflow of cutting fluid will pollute the environment and easily cause safety and quality accidents;

(4) The high cost of cutting fluid transmission, recovery, filtering and other devices and their maintenance costs increase production costs.

Due to the above reasons, the dry cutting process has been widely used in western industrialized countries. The Red Crescent dry cutting process recommended by the American Makino company can not only give full play to the cutting performance of the tool, but also greatly improve productivity compared with wet cutting. The mechanism is that due to the high cutting speed, the heat generated is concentrated in the front of the tool, so that the material near the cutting area reaches a red hot state, and the yield strength decreases, thereby achieving the effect of improving the cutting efficiency. The prerequisite for the use of the red crescent dry cutting process is that at higher cutting temperatures, the strength of the material to be cut is significantly reduced and becomes easier to cut, and the strength of the tool material must have better red hardness and thermal stability under the same state , But also have better abrasion resistance and adhesion resistance.

The tool materials suitable for dry cutting process include ceramics, cermets, coated cemented carbide and PCBN tool materials, etc., but in terms of red hardness and thermal stability, PCBN material is the most suitable tool for dry cutting process Material, and because the PCBN tool material has the above advantages, it is more suitable for dry cutting under high-speed conditions. The comparison between dry cutting and wet cutting of gray cast iron with PCBN cutting tool can be seen: PCBN is used for high-speed dry cutting. In this case, it has a higher tool life than wet cutting.

Suitable for automatic processing and processing of difficult-to-process materials

PCBN knife has high hardness and wear resistance, and can process high-precision parts (small size dispersion) at high cutting speed for a long time, greatly reducing the number of tool changes and the time it takes for tool wear compensation to stop. . Therefore, it is very suitable for CNC machine tools and processing equipment with a high degree of automation, and can make the equipment's high efficiency fully exerted.

In the application of difficult-to-machine materials, PCBN tools also show their excellent performance, such as surface spray welding (coating) materials processing, processing with other materials, tool life is extremely low, and it cannot be processed by grinding methods. PCBN is the only suitable tool material; another example is the high-alloy wear-resistant cast iron used in petroleum power station equipment. The use of PCBN tools increases the cutting efficiency by more than 4 times compared with cemented carbide tools, and the cost of a single tool is reduced to 1/ 5. In addition, PCBN tools also show good cutting performance in the cutting of sintered materials such as cemented carbide.