The Function of Aluminum in Zinc Alloy
The aluminum content is controlled at 3.8 ~ 4.3%. Mainly considering the required strength and fluidity. Good fluidity is a necessary condition for obtaining a complete, dimensionally accurate, smooth surface casting. Here are the function of aluminum in zinc alloy.
1 Improves the casting properties of the zinc alloy and increases its fluidity. It also refines the grains and causes solid solution strengthening to improve mechanical properties.
2 Reduce the ability of zinc to react with iron and reduce the erosion of iron materials such as goosenecks, molds and crucibles.
Aluminum has an extremely strong influence on the fluidity and mechanical properties of zinc alloys. The fluidity reaches a maximum at an aluminum content of 5%; it drops to a minimum at 3%. The effect of aluminum on impact strength. The impact strength reaches a maximum at 3.5% aluminum content; it drops to a minimum at 6%. The aluminum content exceeds 4.3% and the alloy becomes brittle. If the aluminum content is lower than the specified range, it is difficult to fill the thin-walled parts, and there is a possibility of cooling and cracking after casting. The unfavorable effect of aluminum in zinc alloys is the production of Fe2Al3 scum, causing its content to decrease.