The materials of die casting mold
used for aluminum alloy should have good thermal conductivity and thermal fatigue resistance. The materials of die casting mold are not easily oxidized under high temperature, and can resist to adhesion of liquid metals, having lower coefficient of thermal expansion. The materials of die casting mold has less deformation of heat treatment and good hardenability.
According to different processing methods, aluminum alloy can be classified into wrought aluminum alloy and cast aluminum alloy.
Wrought aluminum alloy can sustain pressure process. It can be processed into aluminum alloy materials having different forms and dimensions, which are mainly used for manufacturing aviation equipment, construction doors and windows.
Wrought aluminum alloy can be classified into non-heat-treated strengthening aluminum alloy and heat-treated strengthening aluminum alloy. Non-heat-treated strengthening aluminum alloy refers to that mechanical property of aluminum alloy cannot be improved through heat treatment. Cast aluminum alloy only can be strengthened through cold working deformation, mainly including high purity aluminum, commercial high-purity aluminum, commercial purity aluminum and antirust aluminum. The mechanical properties of heat-treated strengthening aluminum alloy can be improved by quenching and other heat treatments. It can be classified into duralumin, wrought aluminum, ultralumin and particular aluminum alloy.
Based on chemical components, cast aluminum alloy can be classified into aluminum-silicon alloy, aluminum copper alloy, aluminum magnesium alloy, aluminum-zinc alloy and aluminum rare earth alloy. Among that, aluminum-silicon alloy contains eutectic silicon aluminum alloy and single eutectic aluminum alloy. The basic process of die casting mould is that the liquid metal is injected into cavity of mold at a low or high speed. Die casting mold has mobile cavity. The mold forces and forges with the cooling of liquid metal, which can eliminate the defect shrinkage porosity of workblank, but also make the internal of workblank reach crushing grain in forging state. The mechanical properties of workblank have been improved significantly.