CASTING MAGNESIUM ALLOY AND PROCESS FOR PRODUCTION OF CAST MAGNESIUM ALLOY

摘要

Amagnesiumalloy for casting according to the present invention is characterized in that , when the entirety is taken as 100% by mass, it includes copper (Cu) in an amount of from 0.5% by mass or more to 10% by mass or less, calcium (Ca) in an amount of from 0.01% by mass or more to 3% by mass or less, and the balance comprising magnesium (Mg) and inevitable impurities. Since the magnesium alloy for casting according to the present invention includes Cu whose heat conductivity is high in a predetermined amount, it is good in terms of heat-conducive ability. The heat-conductive ability is improved by carrying out heat treatment. Moreover, in the magnesium alloy for casting according to the present invention being in as-cast state, grain-boundary crystallized substances including Cu and Ca constitute three-dimensional networks in grain boundaries between Mg crystalline grains. In the network-shaped grain-boundary crystallized substances, grain-boundary sliding, which becomes active when they become high temperature, is suppressed, and thereby high-temperature strength and creep resistance improve.