Researchers at Japan’s National Institute for Materials Science and Tohoku University have developed a zinc oxide (ZnO) coating that reduces friction and resists heat in bearings.

Tests of commercially available bearings coated with ZnO and then integrated into a jet engine generator demonstrated a reduction of the coefficient of friction by about one-third and lower fuel consumption, the group reports.

Bearings coated with zinc oxide helped cut friction and heat in this small jet engine driven generator.The research was conducted as part of the Green Tribology Network project led by the university and NIMS. One goal of the program is to develop advanced environmental materials that save energy in mechanical components, possibly improving efficiency in automobiles and other systems.

To help speed the commercial application of their findings, the project team also developed techniques for applying ZnO coating to bearings. Their application method controlled the crystal orientation of the material by rotating bearing balls in cage-shaped sample holders.

The researchers expect the coating could find use well beyond bearings, in other mechanically driven parts requiring friction reduction, since it can be used in high temperatures, in oil, under vacuum, and in atmosphere.