Casting method and alloy composition for forming a cast part having a combination of excellent high temperature deformation characteristics, malleability and corrosion performance

摘要

A process for casting a magnesium alloy consisting of 2.0-6.00% by weight of aluminium, 3.00-8.00% by weight of rare earth metals (RE-metals), the ratio of the amount of RE-metals to the amount of aluminium expressed as % by weight being larger than 0.8, at least 40% by weight of the RE-metals being cerium, less than 0.5% by weight of manganese, less than 1.00% by weight of zinc, less than 0.01% by weight of calcium less than 0.01% by weight of strontium and the balance being magnesium and unavoidable impurities, the total impurity level being below 0.1% by weight, wherein the alloy is cast in a die the temperature of which is controlled in the range of 180-340° C., the die is filled in a time which expressed in milliseconds is equal to the product of a number between 5 and 500 multiplied by the average part thickness expressed in millimeter, the static metal pressures being maintained during casting between 20-70 MPa and is subsequently intensified up to 180 MPa.