How to choose the tool when encountering difficult-to-machine materials in the cutting field?
        When cutting difficult-to-machine materials, the tool will be worn out in most cases. Therefore, users are required to carefully select the tool types and cutting conditions when cutting difficult-to-machine materials to obtain the ideal machining effect.Cutting processing is roughly divided into turning, milling, and center-tooth-based cutting (end face cutting of drills and end mills, etc.). The cutting heat of these cutting processes has the same effect on the tool tip. Turning is a continuous cutting. The cutting force on the tip of the tool does not change significantly, and the cutting heat continuously acts on the cutting edge; milling is a kind of intermittent cutting. The cutting force is intermittently acting on the tip of the cutting edge, and vibration will occur during cutting. The heat effect of the sharp edge is heating during cutting and cooling during non-cutting alternately, and the total amount of heat received is less than during turning.

      In cutting, the tool wear that usually occurs includes the following two forms: wear due to mechanical action, such as chipping or abrasive wear, etc.; wear due to thermal and chemical effects, such as adhesion, diffusion, and corrosion Etc. wear, as well as breakage, thermal fatigue, and thermal cracking caused by the softening and melting of the cutting edge. When cutting difficult-to-machine materials, the above-mentioned tool wear occurs within a short period of time. This is due to the fact that there are many factors that promote tool wear in the processed material. For example, most difficult-to-machine materials have the characteristics of low thermal conductivity, and the heat generated during cutting is difficult to diffuse, resulting in high temperature of the cutting edge of the tool, and the cutting edge is extremely affected by heat. As a result of this effect, the bonding strength of the binder in the tool material will decrease at high temperatures, and particles such as WC (tungsten carbide) will be easily separated, thereby accelerating tool wear. In addition, the components in the difficult-to-machine material and some components in the tool material react under cutting high temperature conditions, and the components appear, fall off, or generate other compounds, which will accelerate the formation of chipping and other tool wear phenomena.

      When cutting high-hardness and high-toughness materials, the temperature of the cutting edge is very high, and tool wear similar to that of difficult-to-machine materials will also occur. For example, when cutting high-hardness steel, compared with cutting general steel, the cutting force is greater. Insufficient tool rigidity will cause chipping and other phenomena, which will make the tool life unstable and shorten the tool life, especially for workpieces that generate short chips. When using materials, craters wear near the cutting edge, and tool breakage often occurs in a short period of time. When cutting super heat-resistant alloys, due to the high temperature and hardness of the material, the cutting force is concentrated on the tip of the cutting edge, which leads to plastic deformation of the cutting edge, and the boundary wear caused by work hardening is also more serious.