Mixed messages

摘要

The all-aluminium volume-production car seemed at one stage to be a realistic aim. But the real growth for the lightweight metal seems to be coming from multi-alloy formulations and mixed materials. Perhaps having the atomic number 13 doesn't help. The most abundant metal in the Earth's crust, aluminium, has a long way to go if it is to replace steel as the default material for car body construction. However, for some applications engineers believe that the benefits of a density one third that of steel more than outweighs the disadvantages of higher raw material cost and relatively low strength, stiffness and formability.