Magnesium Flair: Less ductile than steel, magnesium alloys require special screws and tightening methods

摘要

Magnesium is an attractive material for auto parts. It's 36 percent lighter than aluminum and 78 percent lighter than steel, yet it has a better strength-to-weight ratio than either metal. It's also highly moldable. Magnesium parts can be die-cast with walls as thin as 0.8 millimeter and draft angles of less than 0.5 degree. A large magnesium casting can often replace a steel fabrication comprised of many parts. Automotive assemblers use magnesium alloys to make a host of parts for the interior, chassis and power train, including transmission housings, transfer cases, intake manifolds, support brackets, steering wheels, and instrument panel frames. Since 1990, the use of magnesium alloys in automotive applications has increased 20 percent annually, and a typical vehicle now contains 8 pounds of the metal.