New light metal composite can float your boat

Researchers, including one of Indian-origin, have developed a new lightweight metal composite that can float on water.

A boat made of such lightweight composites will not sink despite damage to its structure. Not only does it have a density lower than that of water, it is strong enough to withstand the rigorous conditions faced in marine environment, the study indicated.

"This new development of very light metal matrix composites can swing the pendulum back in favour of metallic materials," forecast study co-author Nikhil Gupta, professor at New York University Polytechnic School of Engineering.

"The ability of metals to withstand higher temperatures can be a huge advantage for these composites in engine and exhaust components, quite apart from structural parts," Gupta, an alumnus of Indian Institute of Science in Bengaluru, noted.

The new material, developed by a team of researchers from NYU Polytechnic School of Engineering and a US-based company Deep Springs Technology (DST), also promises to improve automotive fuel economy because it combines light weight with heat resistance.

Their magnesium alloy matrix composite is reinforced with silicon carbide hollow particles and has a density of only 0.92 grams per cubic centimetre compared to 1.0 gm/cc of water.

The researchers said that although syntactic foams have been around for many years, this is the first development of a lightweight metal matrix syntactic foam.

Significant efforts in recent years have focused on developing lightweight polymer matrix composites to replace heavier metal-based components in automobiles and marine vessels.

The technology for the new composite is very close to maturation and could be put into prototypes for testing within three years, the researchers noted.

The study appeared in the International Journal of Impact Engineering.