Formation of gas induced shrinkage porosity in Mg-alloy high-pressure die-castings

It is shown that gas pores can facilitate formation of shrinkage porosity in high-pressure die-castings. Air in the gas pores is an efficient heat-insulating medium that retards heat transfer in the melt as compared to regions without porosity, leading to lower local solidification rate, which can induce shrinkage porosity formation. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.