Mould parts necessary features 1, wear-resistant plastic modified blank in the mold cavity, the flow and sliding along the cavity surface, make the cavity surface with a dramatic friction between billet, resulting in mould failure due to wear and tear.
So the wear resistance of materials is one of the most basic, the most important performance of mould.
Hardness is the main factors influencing the abrasion resistance.
Under normal circumstances, the mould parts of hardness is higher, the smaller the amount of wear and tear, abrasion resistance and the better.
In addition, abrasion resistance and carbides in the material type, quantity, shape, size and distribution.
2, strong toughness die working conditions are very bad, some often bear greater impact load, which can lead to brittle fracture.
Suddenly brittle fracture at work to prevent mold parts, mold with high strength and toughness.
Mould toughness mainly depends on the material state of carbon content, grain size and organization.
3, die working process, the fatigue fracture performance under cyclic stress of long-term effects, often leads to fatigue fracture.
Its form has little energy repeated impact fatigue fracture and tensile fatigue fracture contact fatigue fracture and fatigue fracture.
Fatigue fracture properties of mold mainly depends on the strength, toughness, hardness, and the content of inclusions in the material.
4, high temperature performance when the mould working temperature is higher, can make the hardness and strength, cause mould early wear or produce plastic deformation and failure.
Therefore, die material should have high tempering stability, resistance to ensure that the mold in the working temperature, has high hardness and strength.
5, cold and hot fatigue resistance of some mould in the process of work is in a state of repeated heating and cooling, the cavity surface tension, pressure and stress effect, cause surface cracking and spalling, increase the friction, obstacles to plastic deformation, reduces the dimension precision, resulting in mould invalidation.
Cold and hot fatigue is one of the main form of hot-work die failure, help the mould should have high resistance to cold and hot fatigue performance.
6, corrosion resistance, some plastic die at work, such as elements, such as chlorine, fluorine plastic of heat decomposition after precipitation HCI, HF, such as strong erosion gas, erosion surface of mould cavity, increasing its surface roughness, aggravate the wear failure.