Design of die casting components
is an important part of die casting manufacture. How to design a die casting component? This paper will discuss this topic from several aspects.
First. Four aspects involved in design of die casting components.
A.Demands on shapes of components.
B.Processing property of die castings.
C.Dimensional accuracy and requirements on surface of die castings.
D.Confirmation of die joint.
Second. Principles for design of die casting components.
A.Choosing the right materials.
B.Confirming dimensional accuracy of die casting parts in suitable ways.
C.Try one’s best to make sure even thickness.
D.Processing corners into fillets and avoiding sharp corners.
Third. Design demands on die casting parts.
1. Requirements on shapes and structures of die casting parts.
A.The internal side concave should be eliminated.
B.Avoiding or reducing core pulling parts.
C.Avoiding crossed cores.
Suitable structures of die casting parts can not only simplify the structure of moulds to decrease costs, but also improve quality of die casting parts.
2. Requirements on thickness of die casting parts.
Thickness of die casting parts are closed related to the whole manufacturing process. It influence the calculation of filling time, selection of flow gates, calculation of coagulation time, analysis of mold temperature gradient, functions of pressures and so on.
A.Over-hick wall thickness will obviously result in declining mechanical property. Die casting parts with thin wall thickness have good compactness, this relatively improving their strength and resistances to pressures.
B.Excessive thin wall thickness may lead to poor filling of liquid aluminum. Thus the molding process will be difficult and welding of aluminum alloys would be poor. As to the die casting part, cold shut may happen to the surface of it.
C.With the increase of wall thicknesses, defects like pores, shrinkage cavities will increase at the same time. Therefore, the wall thickness should be even and as small as possible on the premise that die casting parts have enough strength and rigidity.
3. Requirements on casting ribs.
Casting ribs are used to improve strength and rigidity of the component after making the wall thickness thinner. This can prevent die castings from shrinkage distortion. It can also avoid transformation when the part is ejected from moulds.
4. Requirements on fillets.
All connections between walls on a die casting parts should be designed to fillets. Only parts that are confirmed as die joints can use other kind of connection. Fillets should have suitable diameters. Excessive small fillets may result in cracks while excessive big fillets may cause shrinkage cavities and porosity.
5. Requirements on angles.
The angles can reduce frictions between the die casting part and the mould cavity. Thus the part can be taken out easily. It can protect the surface of die casting parts from staining and prolong service life of die casting moulds.