Diecastability and properties of Mg-Al-Sr based alloys

The need to develop magnesium diecasting alloys for transmission and engine components is leading to active R&D in high temperature magnesium alloy development. Mg-Al-Sr based alloys are a new addition to the creep-resistant magnesium alloys that have been developed in recent years. This paper presents the results of an investigation into the diecastability of Mg-Al-Sr and Mg-Al-Sr-Ca alloys. The mechanical properties (tensile, creep, etc) of both separately diecast test specimens and specimens cut from a diecast automotive part (valve cover) are high at both room temperature and elevated temperatures. The creep resistance shows improvement over existing magnesium diecasting alloys AS41 and AE42. The corrosion resistance of the alloys compares well with the high purity AZ91D and AM60B alloys.