Automotive Applications of Magnesium and Its Alloys

Today’s interest in magnesium alloys for automotive applications is based on the combination of high strength properties and low density. For this reason magnesium alloys are very attractive as structural materials in all applications where weight savings are of great concern. In automotive applications weight reduction will improve the performance of a vehicle by reducing the rolling resistance and energy of acceleration, thus reducing the fuel consumption and moreover a reduction of the greenhouse gas CO2 can be achieved. The present paper gives an overview on the actual status of the development of magnesium alloys and technologies for application in the automotive industries. The development of new cast or wrought alloys and the optimisation of existing or new processes for the production of magnesium parts are discussed. Magnesium has a long history in automotive applications. The decrease of magnesium use in automotive applications in the seventies was greatly related to its prize volatility and also to lack of knowledge. Stricter legislative rules (CAFE) and voluntary commitments to reduce the average fuel consumption have nowadays revived the interest in magnesium. strength magnesium alloys show similar or even better values than aluminium and many commercial steels (Fig. 1). With the increasing use of magnesium the cost per tonne is coming down, which makes it more competitive from the economic point of view too. The consumption of primary magnesium shows a broad increase in the last 20 years whereas North America is the main consumer followed by the western part of Europe and Japan 1. Most of the available magnesium (40 %) is still used for alloying aluminium and only about 34% is directly used for magnesium parts, which can be divided into casting applications (33.5%) and wrought materials (0.5%) 2. It was estimated that the market for magnesium die castings will grow from 105 tons in 2000 to twice this amount in 2006. Approximately 80 % of this market is expected to go towards die casting automotive parts1. Normally the price for magnesium