Microstructural refinement of AZ91D die-cast alloy by intensive shearing

The melt conditioned high pressure die casting (MC-HPDC) process is introduced, where Mg-alloy AZ91D was intensively sheared at different temperatures over the liquidus temperature using the melt conditioning by advanced shear technology (MCAST) process prior to high pressure die casting (HPDC). The resultant microstructures were investigated and compared to those obtained from conventional HPDC. This study shows for the first time that the implementation of intensive shearing in the fully liquid state has produced high integrity Mg-alloy castings with fine and uniform microstructure, reduced cast defects and improved mechanical properties.