With the rapid development of CNC machining technology and the widespread use of CNC machine tools, tool materials are constantly updated and developed. High-speed cutting has become an indispensable and important method in modern cutting. The cutting speed of high-speed cutting is 5-10 times that of conventional cutting, and new requirements are put forward for tool materials, tool structure, geometric parameters, etc., especially for tool materials. It has high strength, toughness and hardness, good thermal stability and thermal hardness, good high temperature mechanical properties, small chemical affinity and wear resistance. Here we discuss the tool materials and performances for high-speed cutting and their reasonable selection measures.
Classification and performance of high-speed cutting tools
The coated tool is to coat a hard wear-resistant metal compound film on the tool base to achieve the purpose of improving the hardness and wear resistance of the tool surface. The commonly used tool matrix materials mainly include high-speed steel, cemented carbide, cermet and ceramics. Coated tools can be divided into hard-coated tools and soft-coated tools. The coating materials of hard-coated tools mainly include titanium nitride (TiN), titanium carbide (TiC), aluminum oxide (Al2O3), titanium carbonitride (TiCN), titanium aluminum nitride (TiAlN), titanium aluminum carbonitride (TiAlCN) and so on. The main characteristics of hard-coated tools are high hardness and good wear resistance. The soft-coated tool is a high-speed steel tool with MoS2 and WS2 as coating materials. The soft-coated tool can reduce friction, cutting force and cutting temperature. The coating can be a single coating, a double coating or multiple coatings, or even a composite coating composed of several coating materials. The composite coating can be TiC-Al2O3-TiN, TiCN and TiAlN multiple composite coatings, and the latest development of TiN/NbN, TiN/CN and other multiple composite composite films. TiN coating has high hardness and good wear resistance. TiC coating has low affinity with metal and strong oxidation resistance. TiAlN has good high-speed cutting performance, and Al2O3 coating has good thermal stability. TiAlN layer has excellent performance in high-speed cutting, and the maximum cutting temperature can reach 800℃.