Researchers have found a way to use fly ash – a byproduct of coal combustion – as an additive to create lightweight metal foams that could replace heavy aluminum and magnesium parts in automobiles.
Nikhil Gupta, associate professor of mechanical and aerospace engineering at Polytechnic Institute of New York University’s Composites Materials and Mechanics Laboratory, and collaborators from the University of Wisconsin-Milwaukee say the fly ash metal foams could be easily incorporated into vehicle manufacturing, reducing the vehicle’s overall weight by 8 percent and, possibly, increasing its fuel economy.
“As a starting point, these materials are ideal replacements in automotive parts that aren’t load-bearing,” says Gupta. “For example, engine and wheel covers and intake manifolds, where the weight and strength of solid metal doesn’t provide any benefit- in fact, it just costs more and weighs more.”
With more than 70 million tons of fly ash produced each year, researchers and manufacturers have experimented with using the material in carpeting and kitchen counter tops to bowling balls and as filler for golf courses. Also, under the Bush Administration, the U.S. EPA supported the use of coal ash as a cement substitute.
Coal ash application doesn’t come without its controversy. While power plant executives say the material is “safe as dirt,” the U.S. EPA says there have been no investigations into the safety of “beneficial use” of coal ash in products.
More than half of the coal ash produced each year is landfilled. According to NYU Poly, technologies like Gupta’s could contribute to a savings of more than $1 billion in disposal costs. Additionally, Gupta says the metal foam’s usage isn’t limited to the automotive industry. This technology could be applied to any product containing aluminum or steel.