The structural design of Xavier’s die-casting parts is the first step in a die-casting job. The rationality of the design and the adaptability of the process will affect the smooth progress of the follow-up work, such as the selection of the parting surface, the opening of the gate, the layout of the ejection mechanism, the structure of the mold and the difficulty of manufacturing, the law of alloy solidification and shrinkage, the guarantee of casting accuracy, and defects. The type of die-casting parts, etc., will be premised on the pros and cons of the die casting itself.
Processability of die casting structure:
1) Try to eliminate the undercut inside the casting to make the mold structure simple.
2) Try to make the wall thickness of the casting as uniform as possible, and use ribs to reduce the wall thickness and reduce defects such as pores, shrinkage holes, and deformation of the casting.
3) Try to eliminate deep holes and deep cavities on castings. Because the small core is easy to bend and break, the filling and exhaust of the deep cavity are poor. Zinc alloy mold
4) The designed casting should be easy to demould and core-pull.
1. wall thickness
1) The wall thickness of die castings is related to performance.
2) The wall thickness of the die casting affects the state of the molten metal filling the cavity, and ultimately affects the surface quality of the casting. Zinc Alloy Mould Design|
3) The wall thickness of the die casting affects the consumption and cost of metal materials.
When designing die castings, in order to ensure the reliability of strength and stiffness, it is believed that the thicker the wall, the better the performance; in fact, for die castings, as the wall thickness increases, the mechanical properties decrease significantly. The reason is that in the die casting process, when the molten metal enters the cavity at high pressure and high speed, it cools and solidifies quickly after contacting the surface of the cavity. A layer of fine-grained structure is formed on the surface of the chilled die-casting, and the thickness of this dense fine-grained structure is about 0.3, so the thin-walled die-casting has higher mechanical properties. On the contrary, the grains in the center layer of thick-walled die-casting parts are larger, and defects such as internal shrinkage cavities, pores, and outer surface depressions are easy to occur, so that the mechanical properties of die-casting parts decrease with the increase of wall thickness.
With the increase of wall thickness, more metal material is consumed, and the cost also increases. However, if the minimum wall thickness is calculated only from the structure, and the complexity of the casting is ignored, it will also cause the liquid metal to fill the cavity in an unsatisfactory state, resulting in defects. On the premise of meeting the functional requirements of the product, comprehensively considering the influence of each post-processing process, to obtain good formability and processability with the lowest metal consumption, it is better to adopt a normal and uniform wall thickness.