The mold needs to have the performance
With the development of the society, the mould of widespread application in many areas, mold designers, must have a rich experience in design and injection molding, these factors must be considered and the relationship between injection molding conditions and its apparent factors, because of the bad die working conditions are compared, therefore, need to mold need to have a lot of performance.
Folding properties
When the working temperature of the mold is higher, the hardness and strength will be reduced, leading to early wear or plastic deformation of the mold and failure.Therefore, the mold material should have higher tempering stability to ensure that the mold at the working temperature has a higher hardness and strength.
Wear resistance
When the blank is plastic deformed in the mold cavity, it flows and slides along the surface of the mold cavity, causing severe friction between the mold surface and the blank, which will lead to failure of the mold due to wear.Therefore, the wear resistance of the material is one of the basic and very important properties of the mold.
Hardness is the main factor that affects wear resistance.Generally speaking, the higher the hardness of the mold parts, the less wear, wear better.In addition, wear resistance is also related to the type, quantity, shape, size and distribution of carbide in the material.
Folding strength
Most of the working conditions of the mold are very harsh, and some of them usually bear a large impact load, resulting in brittle fracture.In order to prevent the mold parts from breaking suddenly when working, the mold should be of high strength and toughness.
The toughness of the mold mainly depends on the carbon content, grain size and microstructure.
Folding fatigue fracture performance
In the process of die working, fatigue fracture is often caused by long-term cyclic stress.Its forms include repeated impact fatigue fracture of small energy, contact fatigue fracture of tensile fatigue fracture and bending fatigue fracture.
The fatigue and fracture properties of the mold mainly depend on the strength, toughness, hardness and the content of inclusions in the material.
Folding resistance to cold and heat fatigue
Some molds are in the state of repeated heating and cooling during the working process, which makes the surface of the cavity subject to tension and pressure change stress, causing the surface crack and spalling, increasing the friction force, hindering the plastic deformation and reducing the dimensional accuracy, thus leading to the failure of the molds.Cold and heat fatigue is one of the main forms of failure of hot work die.
Folding corrosion resistance
When some molds, such as plastic molds, are working, due to the presence of chlorine, fluorine and other elements in the plastics, after being heated, strong corrosive gases such as HCI, HF and so on are decomposed and precipitated, eroding the surface of mold cavity, increasing the roughness of its surface and aggravating the failure of wear.