(May 13, 2015) Researchers
have demonstrated a new metal matrix composite that is so light that it can
float on water. A boat made of such lightweight composites will not sink
despite damage to its structure. The new material also promises to improve
automotive fuel economy because it combines light weight with heat resistance.
Although syntactic foams have been around for many years,
this is the first development of a lightweight metal matrix syntactic foam. It
is the work of a team of researchers from Deep Springs Technology (DST) and the
New York University Polytechnic School of Engineering.
Their magnesium alloy matrix composite is reinforced with
silicon carbide hollow particles and has a density of only 0.92 grams per cubic
centimeter compared to 1.0 g/cc of water. Not only does it have a density lower
than that of water, it is strong enough to withstand the rigorous conditions
faced in the marine environment.