Patent ID: 6467527
Filing Date: 2002-10-22
Classification: B22D

Abstract:
A method for die-casting a magnesium alloy, which comprises the step of casting a die cast product free of any hot tearing, shrinkage tearing and shrinkage cavity starting from a magnesium alloy comprisingi) 1 to 10% by weight of aluminum; ii) at least one member selected from the group consisting of 0.2 to 5% by weight of a rare earth metal, 0.02 to 5% by weight of calcium and 0.2 to 10% by weight of silicon; iii) not more than 1.5% by weight of manganese, and iv) the balance of magnesium and inevitable impurities, using a cold chamber die-casting machine, by a) maintaining ,a temperature of the molten magnesium alloy from 650 to 750Â° C.; b) setting a charging velocity of the molten metal from {fraction (1/100)} to {fraction (10/100)} second; and c) setting an intensified pressure after the charging at a level of not less than 200 kgf/cm21, wherein a plurality of gates are provided per cavity, each gate is directly connected to each of a plurality of separate runners, each runner directly connects a sprue to each gate, wherein the plurality of gates are disposed so that the molten metal for flow in each runner is uniform with the metal flow in the other runners and a distance of a gate-free portion between two neighboring gates is set at a distance of not more than 10 mm.