COMPUTATIONAL MULTI-SCALE MODELING OF THE MICROSTRUCTURE AND SEGREGATION OF CAST Mg ALLOYS AT LOW SUPERHEAT

摘要

It is well known that casting at low superheat has a stronginfluence on the solidification structures of the cast alloy.Recent studies on casting magnesium AZ alloys at lowsuperheat using the Magnetic Suspension Melting (MSM)process have shown that the cast alloy exhibit a fineglobular grain structure, and the grain size depend on thecooling rate. This paper describes a stochastic mesoscopicmodel for predicting the grain structure and segregation incast alloys at low superheat. This model was applied topredict the globular solidification morphology and soluteredistribution of Al in cast Mg AZ31B alloy at differentcooling rates. The predictions were found to be in goodagreement with the observed grain structure and Alsegregation. This makes the model a very useful tool foroptimizing the solidification structure of cast magnesiumalloys.