The influence of aluminum plating zinc alloy composition

Zinc alloy die casting is usually composed of 96% 4% of zinc, aluminum, and copper and magnesium. And other silicon, iron, cadmium, tin, lead, etc., as the existence of impurities.

Pressure diecasting of zinc alloy, aluminum components inside to refine crystal particles, strengthen the strength of castings, can also reduce molten zinc to mold the erosion of black metal, with the improvement of the aluminum component content, strong casting coating and impact resistance value is obvious improve, but aluminum is higher than 4.5%, the impact toughness is on the decline. If die casting surface will need to be in the plating processing, such as nickel chrome plating, high aluminum components will cause poor adhesion, ordinary zinc alloy plating process cannot be good for high aluminum chrome.

Copper used to improve its mechanical properties, but also can improve the strength and hardness of alloy castings, but not higher than 1.5%.

Trace amounts of magnesium by 0.01% ~ 0.04%, zinc aluminum alloy has creep performance.

Other silicon, iron, cadmium, tin, lead to the presence of impurities such as, can make zinc alloy casting produce when exposed to intergranular corrosion in the corrosion environment, the iron with aluminum to produce hard iron and aluminum compounds, this will give before plating processing of difficult machining and grinding and polishing.