1. Broken: Graphite mold directly contacts the matrix powder containing diamond. The contact surface is in a high pressure state. The hardness of diamond and graphite mold is too poor. The surface of the mold that is in contact with diamond tool head will produce concave pits.

Second, the type of damage: During the sintering process, the matrix powder infiltrates into the oxidation gap of the graphite mold under the melting state, resulting in the adhesion between the tool head and the mold, making it difficult for molding. The repeated attack of the mold can remove the mold, which causes the lack of edges and metal pit in the mold.

Third, the wear size of graphite molds is very poor: some substrate powder will be squeezed out of the mold surface in the melting state to attach to the graphite material. Before using the mold next time, metal residues must be removed manually, which causes the shape and size of the mold to exceed the tolerance.

Fourth, surface oxidation and cracking: Because there is no protection of the atmosphere during the hot -pressing sintering process, the graphite and the air are directly contacting, and the surface oxidation will inevitably occur at high temperature. The higher the temperature, the faster the oxidation speed; Only leave some carbon and gray points, stones can be found at the actual production site. After a period of time, the surface of the mold will produce pores and carbon powder.

V. Fracture: The cause of this damage is that the side plate of the diamond knife head is not tightly clamped, resulting in an unbalanced pressure drop on the head, leading to the horizontal shear force.