1、Abrasion resistance
When the blank is plasticized in the mold cavity, it flows and slides along the surface of the cavity, causing violent friction between the surface of the cavity and the blank, which leads to the failure of the mold due to wear. Therefore, the wear resistance of the material is one of the most basic and important properties of the mold.
Hardness is the main factor affecting wear resistance. Generally speaking, the higher the hardness of the mold parts, the smaller the wear, and the better the wear resistance. In addition, wear resistance is also related to the type, number, form, size and distribution of carbide in the material.
2、Strong toughness
Most of the working conditions of the mold are very bad, and some of them are often subjected to large impact load, which leads to brittle fracture. To prevent the mold parts in the work of sudden brittle fracture, mold to have high strength and toughness. Mold toughness mainly depends on the material carbon content, grain size and tissue state.
3、Fatigue fracture performance
Mold work process, under the long-term role of cyclic stress, often lead to fatigue fracture. The form of small energy multiple impact fatigue fracture, tensile fatigue fracture contact fatigue fracture and bending fatigue fracture. The fatigue fracture performance of the mold mainly depends on its strength, toughness, hardness, and the content of inclusions in the material.
4、High temperature performance
When the working temperature of the mold is high, it will make the hardness and strength drop, resulting in early wear or plastic deformation and failure of the mold. Therefore, the mold material should have a high tempering stability to ensure that the mold in the working temperature, with high hardness and strength.
5、Hot and cold fatigue resistance
Some molds in the work process in the repeated heating and cooling state, so that the cavity surface by the role of tensile, pressure variable stress, causing surface cracking and spalling, increasing friction, hindering plastic deformation, reducing the dimensional accuracy, thus leading to mold failure. Hot and cold fatigue is one of the main forms of hot mold failure, help this kind of mold should have a high resistance to hot and cold fatigue performance.
6、Corrosion resistance
Some molds such as plastic mold at work, due to the presence of chlorine, fluorine and other elements in the plastic, decomposition after heat precipitation of HCI, HF and other strong aggressive gas, erosion mold cavity surface, increase its surface roughness, intensify the wear loss effect.
