Tribology of rejuvenated CuZr-based amorphous alloys

Abstract Cryogenic thermal cycling was done for the rejuvenation of Cu46Zr47Al7 and Cu45Zr47Al7Ti1 amorphous alloys. The effect of rejuvenation on the tribological behavior of these two amorphous alloys was investigated against Si3N4 ball by reciprocating sliding wear test. A significant improvement in the tribological properties was seen for the rejuvenated Cu46Zr47Al7 alloy, which showed the lowest COF and wear rate among the studied alloys. Rejuvenation resulted in an increase in H/E and H3/E2 ratios, where H = hardness and E = elastic modulus. The Cu45Zr47Al7Ti1 amorphous alloy showed relatively smaller increase in relaxation enthalpy after rejuvenation. The wear mechanisms were determined to be mainly adhesive, fatigue, and oxidative wear. Our results indicate that rejuvenation may be an effective way to improve the tribological performance of metallic glasses both in the form of bulk alloys as well as coatings.