Cemented carbide is made by high-pressure sintering of WC (tungsten carbide), TiC (carbonized carbide) and Co (drilled) powders with high wear resistance and high heat resistance, followed by high-temperature sintering. As a knot, the hardness of the cemented carbide is HRC74-82, which has a very high red hard temperature. The hardness required for cutting can be maintained at a high temperature of 800-1000 ° C. The cutting speed of a steel cutting tool can reach 100-300 m / min. The cutter can be used for high-speed cutting. The disadvantage is that the toughness is higher. Poor, brittle, and impatient, hard alloys are generally made into blades of various shapes, welded or clamped on the body. As shown in Figure 1-4, the commonly used cemented carbide has tungsten drill. There are two big categories of tungsten and diamonds.

(1) Tungsten drill (YG). It consists of tungsten carbide and diamond and is suitable for processing brittle materials such as cast iron and bronze. Commonly used grades are YG3, YG6, YG8, etc. The number on the back indicates the percentage of the drilled amount. The higher the drilled amount, the better the ability to withstand the impact. Therefore, YG8 is often used for roughing, and YG6 and YG3 are often used for semi-finishing and finishing.

(2) Tungsten-titanium drill (YT). It consists of tungsten carbide, carbon carbide and diamond. Adding carbonization can enhance the wear resistance of the alloy, enhance the emulsion temperature of the alloy and plastic material, reduce tool loss, and also Increased hardness; but poor toughness, more brittle, and the ability to withstand collisions, generally used to process plastic materials, such as a variety of steel.

Commonly used grades are YT5, YT15, YT30, etc. The back number is the percentage of carbonization content. The higher the content of carbonization, the better the red hardness; but the lower the content of the drill, the worse the toughness, the less resistant Collision, so YT5 is often used for roughing, and YT15 and YT30 are often used for semi-finishing and finishing.