How to choose Zinc die casting and aluminum die casting

The price of zinc alloy and aluminum alloy is similar. If the structure and die casting process allow, of course, it is more cost-effective to use aluminum alloy. The specific gravity of zinc alloy is about 2.5 times that of aluminum alloy, and the price is similar, so the material cost of zinc alloy is two or three times more expensive than that of aluminum alloy. Now many companies want to use aluminum alloys instead of zinc alloys in order to save costs, but some products cannot be replaced, because the strength, hardness and formability of zinc alloys are much better than aluminum alloys. If your product surface needs to be polished and electroplated , and requires high appearance quality, then it needs to be die-casted with zinc alloy. It is difficult for aluminum alloys to meet high surface quality requirements. Because the surface of aluminum die casting products is prone to pores, the surface texture after electroplating is poor.
Zinc alloy die-casting has better performance and many advantages. Zinc alloy has low melting point, small solidification temperature range, easy filling and forming, small shrinkage tendency, and can die-cast precision parts with complex shapes and thin walls. Zinc die-casting parts have a smooth surface. High dimensional accuracy; low pouring temperature, long service life of the mold, not easy to stick to the mold, and no corrosion of the mold. The mechanical properties of zinc alloy at room temperature are also high, especially the compression resistance and wear resistance are very good.
The most serious disadvantage of zinc alloys is the aging phenomenon. The volume increases and the strength decreases. If the time is too long, the die castings will be deformed or even broken. This is also the main reason why the use of zinc alloys is limited.
Aluminum alloys are much better in performance than zinc alloys, and aluminum alloy die-casting has good die-casting properties, electrical and thermal conductivity, and good cutting performance. The disadvantages are also obvious. Al-Si series alloys are easy to stick to molds, are corrosive to metal crucibles, have large volume shrinkage, and are prone to shrinkage cavities.
At the same time, because of their different effects on the mold, generally speaking, the prices of the molds used for zinc alloy and aluminum alloy die-casting are also different. Zinc alloy die-casting molds are not easy to stick to the mold and do not corrode the mold. Cheaper, and aluminum die casting is easy to stick to the mold and corrode the metal crucible, and the price of the mold required will be higher.


Post time: May-31-2022