The article by FIERF Professor Dr. Mary Wells of Waterloo University (Waterloo, Ontario) in this issue about forging magnesium brings the concepts of lightweighting to the forefront.
Lightweighting, a term that started in the automobile industry in response to calls to increase automotive energy efficiencies, has taken hold in a big way. Generally, the lightweighting process has stimulated research and development in new materials and new ways to use old materials to reduce the average weight of cars and trucks without compromising safety, comfort and other design considerations. But the concept of weight reduction is not limited to automotive applications. The aerospace industry has been dealing with weight-reduction initiatives since its inception, and virtually any increase in a material’s strength-to-weight ratio make it a serious candidate for consideration.
One way to consider the lightweighting process is by substituting materials. A primary example in the automotive industry is to reduce weight by substituting lighter-weight aluminum for some steel components. Plastic was used instead of heavy glass in some windows, as well as for metal in bumper systems. Using these lighter-weight materials results in better gas mileage, improved vehicle handling and less strain on the engine. Carbon-fiber composite materials are also used in automotive applications, but the most-heralded recent use of carbon-fiber composite materials is in the wing sections of Boeing’s 787 Dreamliner.
In Germany, steelmaking companies and the German Forging Association partnered to conduct two phases of their Lightweight Forging Initiative. The Phase I program dealt with studying a medium-sized passenger car, in which they found that, through prudent design and material selection, 92 pounds (42 kg) of weight could be eliminated from powertrain and chassis components alone. In Phase II, a light-commercial vehicle was studied, and it was found that about 220 pounds (99 kg) could be saved in a similar fashion. This publication reported on these Phases in our April and June issues of 2016.
Back in the U.S., the National Institute of Standards and Technology (NIST) established its Center for Automotive Lightweighting (CAL). CAL’s mission is to supply the automotive industry with the data and material models necessary to manufacture reliable components from aluminum and high-strength steels. These are not necessarily forging-specific, but the underlying principles of weight reduction apply nonetheless.
Not surprisingly, the U.S. Department of Energy also weighed in (no pun intended) on the subject since energy efficiency is one of the main goals of the process. So if you are wondering where lightweighting is headed, take your lead from this passage from the DOE’s website: “Advanced materials are essential for boosting the fuel economy of modern automobiles while maintaining safety and performance. Because it takes less energy to accelerate a lighter object than a heavier one, lightweight materials offer great potential for increasing vehicle efficiency. A 10% reduction in vehicle weight can result in a 6-8% fuel-economy improvement. Replacing cast iron and traditional steel components with lightweight materials such as high-strength steel, magnesium (Mg) alloys, aluminum (Al) alloys, carbon-fiber and polymer composites can directly reduce the weight of a vehicle’s body and chassis by up to 50% and therefore reduce a vehicle’s fuel consumption. Using lightweight components and high-efficiency engines enabled by advanced materials in one-quarter of the U.S. fleet could save more than 5 billion gallons of fuel annually by 2030.”
Dean M. Peters, Editor