Impacts of different elements of aluminum alloy die casting on its performance
: silicon can make aluminum alloy
flow good, and reduce the shrinkage to improve pressure resistance. As well as improving its weldability and reducing the coefficient of thermal expansion. Adding a large number of silicon could improve its wear resistance, but the machinability would be worse.
: copper can improve mechanical properties and machinability of aluminum alloy
, but the corrosion resistance and melting fluid flow would be worse and cause hot intermittent fracture.
: a small amount of iron can reduce the shrinkage of aluminum alloy, and make crystallization smaller. But its mechanical properties generally would be reduced, especially when silicon content has reach more than 5% of the alloy. That would produce ternary compounds, and make texture big and fragile.
: manganese are effective to crystal micronization and can prevent shrinkage. But the adding amount of manganese should base on the iron content. Otherwise coarse primary crystal would occur, and its mechanical properties would decline significantly.
: magnesium can improve mechanical properties and machinability of aluminum alloy, but its flowability and pressure resistance would be worse, thermal interruption would also increase obviously. For alloys containing silicon, precipitation hardening of Mg2Si can improve its mechanical properties. In addition, alloy containing over 8% of magnesium can improve mechanical properties after heat treatment .
: nickel can improve mechanical properties of aluminum alloy at high temperature, but if we add more than 5% of nickel, aluminum alloy is prone to shrinkage.
: adding a small amount of titanium can make the crystallization of aluminum alloy smaller, and improve mechanical properties.
: adding zinc and magnesium would improve mechanical properties of aluminum alloy, but its corrosion resistance would reduce. Too much of them would easily cause shrinkage.
: beryllium would oxidize and form a stable protective film on the molten liquid surface so as to prevent Al-Mg series from oxidation when melting, stop the formation of sediment, improve mechanical properties and melt flow.