Gradient structure cemented carbide is a kind of alloy with good surface hardness and internal toughness and other thermodynamic properties.

According to the different internal structures, cemented carbide can be divided into heterogeneous structural alloy and homogeneous structural alloy, and the heterogeneous structural alloy can also be divided into honeycomb structural alloy and gradient structural alloy.

Among them, gradient cemented carbide has different mechanical properties from conventional homogeneous cemented carbide due to its inhomogeneous structure. Especially its sandwich structure can improve the surface hardness and internal toughness of the material at the same time, so it has more advantages in terms of mechanical properties and service life. Generally speaking, the higher the content of tungsten carbide powder, the finer the grain, the higher the hardness of the alloy, and vice versa.

The hardness distribution of gradient structure alloy material is not consistent because of its uneven structure.

The surface layer of gradient structure cemented carbide has high hardness due to the high content of tungsten carbide particles, and the middle layer is rich in drilling phase, with low hardness; Due to the large amount of tungsten phase in the core, the hardness increases again. During the carburizing process, the microhardness of the surface layer and the intermediate layer of the alloy decreases with the prolongation of the carburizing time