For some time, we have seen the auto industry making increasing use of aluminum and high-strength steel in order to produce lighter vehicles that use less fuel and perform better on the road. Now magnesium and carbon fiber are being explored by a number of auto manufacturers. General Motors (GM) says that Magnesium, despite its lower melting point and lower strength when compared to steel, is suitable for large castings and specific parts.
The metal is 33% lighter than aluminum and just as corrosion resistant. Casting and machining does not present any challenges, and because it is workable at lower temperatures, the equipment used to shape the parts will last longer. At present, GM is looking at magnesium as a possible alternative material for car doors and trunks.
The lightweighting benefits of carbon fiber have long been known, but the material was previously too expensive for use in auto manufacture. This seems to have changed, and General Motors are currently designing and testing carbon-fiber wheels that will allow them to shed 40 pounds or more from a vehicle’s overall weight. After all, this material is five times stronger than steel and twice as rigid, besides having the capacity to assume almost any shape.