Commonly used cemented carbides are mainly composed of WC, and are divided into the following categories according to whether other carbides are added:
     

      (1) Tungsten-Cobalt (WC+Co) Cemented Carbide (YG)

       The main components are tungsten carbide (WC) and binder cobalt (Co). Its grade is composed of "YG" ("hard and cobalt" in Chinese Pinyin) and the percentage of average cobalt content. For example, YG8 means average WCo=8%, and the rest is tungsten-cobalt-based cemented carbide of tungsten carbide. It is composed of WC and Co, has high flexural strength and toughness, good thermal conductivity, but poor heat resistance and wear resistance, and is mainly used for machining cast iron and non-ferrous metals. Fine-grained YG-type cemented carbides (such as YG3X, YG6X) have higher hardness and wear resistance than YG3 and YG6 when the cobalt content is the same, and their strength and toughness are slightly worse. They are suitable for machining hard cast iron and austenitic stainless steel. , heat-resistant alloy, hard bronze, etc.

 (2) Tungsten-titanium-cobalt (WC+TiC+Co) cemented carbide (YT)

  The main components are tungsten carbide, titanium carbide (TiC) and cobalt. Its grade is composed of "YT" ("hard, titanium" two characters in Chinese Pinyin prefix) and the average content of titanium carbide. For example, YT15 means average WTi=15%, and the rest is tungsten carbide and tungsten-titanium-cobalt-based cemented carbide with cobalt content. Since TiC has higher hardness and melting point than WC, compared with YG, its hardness, wear resistance and red hardness are increased, its bonding temperature is high, and its oxidation resistance is strong, and TiO 2 will be formed at high temperature, which can reduce the bond. However, it has poor thermal conductivity and low flexural strength, so it is suitable for processing tough materials such as steel.

 (3) Tungsten-tantalum-cobalt (WC+TaC+Co) cemented carbide (YA)

  TaC (NbC) is added on the basis of YG-type cemented carbide, which improves the hardness and strength, thermal shock resistance and wear resistance at room temperature and high temperature, and can be used for machining cast iron and stainless steel.

  (4) Tungsten-titanium-tantalum-cobalt (WC+TiC+TaC+Co) cemented carbide (YW)

  The main components are tungsten carbide, titanium carbide, tantalum carbide (or niobium carbide) and cobalt. This kind of cemented carbide is also called general cemented carbide or universal cemented carbide. Its grade is composed of "YW" (the Chinese phonetic prefix of "hard" and "wan") plus a sequence number, such as YW1. The addition of TaC (NbC) on the basis of YT-type cemented carbide improves the flexural strength, impact toughness, high temperature hardness, oxygen resistance and wear resistance. It can process both steel, cast iron and non-ferrous metals. Therefore, it is often called universal cemented carbide (also known as universal cemented carbide). At present, it is mainly used for processing difficult-to-machine materials such as heat-resistant steel, high-manganese steel and stainless steel.