Magnesium Alloy Development for Automotive Applications

This paper summarizes the development of new cast and wrought magnesium alloys using computational thermodynamics and experimental methods. The work illustrates the role of calculated phase diagrams, solidification paths and phases in predicting and interpreting the final microstructure of Mg-Al-Ca and Mg-Al-Sn cast alloy systems and Mg-Zn-Ce and Mg-Zn-Nd wrought alloy systems. The Mg-Al-Ca alloys show excellent creep resistance due to the formation of high-temperature (Mg,AL)(2)Ca phase. The Mg-Al-Sn alloys are designed for mechanical properties and corrosion resistance by optimizing the Mg17Al12 and Mg2Sn phases in the microstructure. In the Mg-Zn-Ce system, Zn provides strength through solid solution strengthening, while Ce increases the ductility by creating a favorable texture. The Mg-Nd-Zn system provides a heat-treatable alloy based on precipitation hardening for strength and texture softening for ductility.