Sandia National Laboratories engineers wear-resistant metal alloy

Sandia National Laboratories researchers Michael Chandross, left, and Nic Argibay show a computer simulation used to predict the wear resistance of their platinum-gold alloy, and an environmental tribometer used to demonstrate it. Photo by Randy Montoya.

The materials science team at Sandia National Laboratories, Albuquerque, N.M., has engineered a platinum-gold alloy that it believes to be the most wear-resistant metal in the world. It’s 100 times more durable than high-strength steel, making it the first alloy, or combination of metals, in the same class as diamond and sapphire, nature’s most wear-resistant materials.

“We showed there’s a fundamental change you can make to some alloys that will impart this tremendous increase in performance over a broad range of real, practical metals,” said Materials Scientist Nic Argibay, part of the team that recently reported its findings in Advanced Materials.

The ultradurable coating could save the electronics industry more than $100 million a year in materials alone, Argibay says, and make various electronics more cost-effective, long-lasting, and dependable across many industries—from aerospace systems and wind turbines to microelectronics for cell phones and radar systems.

Conventional wisdom says a metal’s ability to withstand friction is based on how hard it is. The Sandia team proposed a new theory that says wear is related to how metals react to heat, not their hardness, and they handpicked metals, proportions, and a fabrication process that could prove their theory.

“Many traditional alloys were developed to increase the strength of a material by reducing grain size,” said John Curry, a postdoctoral appointee at Sandia and first author on the report. “Even still, in the presence of extreme stresses and temperatures, many alloys will coarsen or soften, especially under fatigue. We saw that with our platinum-gold alloy, the mechanical and thermal stability is excellent, and we did not see much change to the microstructure over immensely long periods of cyclic stress during sliding.”