A new metal matrix composite that can float on water (but is still very strong) has been created by researchers at New York University and Deep Springs Technology. This combination could see it being used in boats and even cars, where weight can be a factor.
The material is what is called a syntactic foam, which is made by using hollow particles to reduce weight. In this case the solid material is a magnesium alloy and the hollow particles are silicon carbide spheres. These spheres can withstand pressures of 25,000 PSI before rupturing, which contributes to the metal’s strength both in what they can withstand but also by absorbing energy when they do rupture. The result is a metal that has a density of just 0.92 grams per cubic centimeter, which is just under the 1.0 of water. That means a boat made of this material would still float, even after suffering serious structural damage.
A lot of work has been done over recent years to find strong and light materials, as a means to conserve energy, but being a metal, this stands apart from the plastics normally getting the attention. Metals can withstand high temperatures, which is necessary for components of engines and exhaust systems.