Magnesium Casting Applications in the Automotive Industry

The last ten years has seen the North American automotive industry increasing its use of magnesium castings at an annual rate of around 15% and this rate of growth is expected to continue for at least the next ten years. The main driving force for this increasing use of magnesium is the need to reduce vehicle weight and improve fuel economy. Magnesium alloys are amongst the lightest structural materials available, however, they do cost more per unit mass than competing materials such as steel and aluminum and the automotive industry is reluctant to pay a premium for weight saving. However, in spite of an apparent cost penalty, magnesium castings are currently used in a number of automotive body, chassis and powertrain applications and this paper will review these applications. There is also a significant potential for future growth in the use of magnesium casting by the automotive industry where there may be little or no cost penalty. This is being brought about by a better understanding of the casting design optimization process, the behavior of magnesium during the casting process, particularly the high pressure die casting process, and the development of new and improved magnesium casting alloys. Recent developments in these areas will also be reviewed.