Magnesium casting technology for structural applications

This paper summarizes the melting and casting processes for magnesium alloys. It also reviews the historical development of magnesium castings and their structural uses in the western world since 1921 when Dow began producing magnesium pistons. Magnesium casting technology was well developed during and after World War II, both in gravity sand and permanent mold casting as well as high-pressure die casting, for aerospace, defense and automotive applications. In the last 20 years, most of the development has been focused on thin-wall die casting applications in the automotive industry, taking advantages of the excellent castability of modern magnesium alloys. Recently, the continued expansion of magnesium casting applications into automotive, defense, aerospace, electronics and power tools has led to the diversification of casting processes into vacuum die casting, low-pressure die casting, squeeze casting, lost foam casting, ablation casting as well as semi-solid casting. This paper will also review the historical, current and potential structural use of magnesium with a focus on automotive applications. The technical challenges of magnesium structural applications are also discussed. Increasing worldwide energy demand, environment protection and government regulations will stimulate more applications of lightweight magnesium castings in the next few decades. The development of use of Integrated Computational Materials Engineering (ICME) tools will accelerate the applications of magnesium castings in structural applications.