Pressure casting method of magnesium alloy and metal products thereof

摘要

The present invention provides a pressure casting method of a magnesium alloy. In the method, a molten magnesium alloy is cooled to form a partially molten state containing a solid-phase, and the partially molten state is further cooled to form a solid-phase granularly crystallized solid material. The solid material is partially-melted and pressure cast into a mold by a molding machine. A ratio of primary crystals in said solid material is set to 55 to 65%. The solid material is partially-melted in a solid-phase and liquid-phase coexisting state at a selected heating temperature so that a semi-solid having a thixotropic properties and having the size of a main solid phase of 50 to 250 μm and a solid-phase ratio of 30 to 70% is formed. The semi-solid is pressure cast into a mold through a nozzle while maintaining the semi-solid state to form metal products having a ratio of primary crystals of 20 to 50%.