Comparative Mechanical Properties of AE42 and AJ52x High-Temperature Diecast Magnesium Alloys for Elevated Temperature Applications 2003-01-0188

For environmental reasons, automotive improved fuel efficiency is becoming increasingly important for OEM's. However, consumers are also demanding more in terms of added comfort and safety features. To meet these conflicting requirements, OEM's are turning to the increased usage of light-weight materials, such as magnesium alloys, for automotive components thus allowing for improved fuel efficiency while maintaining the ability to add extra comfort and safety features. Due to the presence of large castings in the power-train, as well as the significant mass in the front of a vehicle, high temperature magnesium alloys that can meet the service requirements of these components are under investigation. The types of mass reduction applications for these alloys include transmission cases, covers and other structural components.

Diecasting, because of its high productivity, is the preferred manufacturing process for these types of components. For this reason, the investigation of high temperature magnesium alloys for these applications focused on die casting alloys. In particular, the objective was to compare the mechanical properties of die cast AE42 and AJ52x. The same multi-cavity dies were used to manufacture samples of each alloy. One of the dies contained cavities of varying thickness allowing the effect of section thickness on mechanical properties to be investigated, without machining and removing the important die cast surface of the samples. This paper provides a comparative compilation of the tensile properties obtained for the two alloys in the investigation for various temperatures and various thicknesses using as-cast samples. Impact, creep, and fatigue properties were also investigated.