Conditions are required for precision parts machining mold processing
In precision parts machining mold processing requires the following conditions to be necessary:
A, abrasion resistance
Variability in the blank plastic mold cavity, the cavity surface along both the flow and slide, so that the cavity surface of the blank generated intense friction between, leading to mold due to wear and failure. So wear resistance of the mold is the most basic, one of the most important performance.
Hardness is a major factor affecting wear resistance. In general, the higher the hardness of the mold parts, the smaller the amount of wear, the better the wear resistance. In addition, the wear resistance of the type, quantity, shape, size and distribution of materials related to carbide.
B, toughness
Mold working conditions are mostly very poor, some often bear a greater impact load, leading to brittle fracture. To prevent mold parts at work suddenly brittle fracture, die to have high strength and toughness.
Mold toughness depends on the carbon content of the material, grain size and organizational status.
C, fatigue fracture properties
Die working process, in the long-term effects of cyclic stress often leads to fatigue fracture. In the form of many small energy impact fatigue fracture, fatigue fracture tensile contact fatigue fracture and fatigue failure.
Fatigue fracture properties of the mold depends on its strength, toughness, hardness, and material content of inclusions.
D, high temperature performance
When the mold into the higher operating temperature, hardness and strength will decrease, leading to early die wear or plastic deformation and failure. Therefore, the mold material should have a high resistance to tempering stability so as to ensure that the mold at the operating temperature, high hardness and strength.
E, resistance to thermal fatigue performance
Some die in the course of their work status of repeated heating and cooling, so that the cavity surface tension, pressure becomes stress, causing surface cracking and spalling, increasing friction and hinder plastic deformation, reducing the dimensional accuracy, resulting in die failure. Thermal fatigue is one of the main forms of hot die failure, such help mold should have a high resistance to thermal fatigue performance.
F, corrosion resistance
Some plastic mold such as at work, due to the chlorine, fluorine and other elements are present in plastics, precipitated decomposition when heated HCI, HF and other strong corrosive gases, erosion of the mold cavity surface, increasing surface roughness, increased wear failure.