Thixomolded® and Thermomechanically Processed Fine-Grained Magnesium Alloys

Thixomolding of Mg alloys produces fine microstructure of about 5-10 micron alpha phase grain size, surrounded by divorced eutectic phases. During the period from 1995 to 2009, this process and microstructure has captured broad applications around the globe - in markets such as electronics (lap-tops, cameras and cell phones), autos, sports and hand tools. Thermomechanical processing has been applied recently to the Thixomolded precursor to further refine the grain size and eutectic phases - providing yield strength above 300 MPa, fatigue strength of 150 MPa along with elongation of 10%. Alloys studied include AM60, AZ61L and thixoblended alloys of higher Zn content. Microstructure is related to processing and properties. Metal/epoxy fiber composites based on this Mg product have demonstrated yield strength of 900 MPa, with E of 90 GPa.