Effect of ZrO ₂ on friction wear behavior of Ti-Zr-Mo alloy under high temperature oxidation condition

Hot-work molds often fail due to severe high-temperature wear. TZM alloy, known for its excellent thermal shock resistance and elevated-temperature strength, is widely used in manufacturing hot-working molds. To improve the high-temperature wear resistance of TZM alloy, this study investigated the effect of ZrO₂(~1.5 wt.%) on its oxidative wear behavior at (~800 °C). Results revealed that increasing ZrO₂ content refined alloy grains and enhanced hardness. Elevated wear temperatures promoted the formation of lubricative oxide layers on the alloy surface, significantly reducing friction. The friction coefficient of 1.5 wt.% ZrO₂/TZM decreased from 0.55 at room temperature to 0.06 at 800 °C, accompanied by a progressive reduction in wear rate. All alloys exhibited optimal wear resistance at 600 °C, while a rapid increase in wear rate occurred at 800 °C due to pronounced molybdenum volatilization induced by excessive thermal energy. At 600 °C, the wear rate of 1.5 wt.% ZrO₂/TZM reached 0.73×10⁻⁵ mm³/(N·m), showing 3.5 times higher wear resistance than pure TZM. The high-temperature wear mechanisms of TZM alloy involved a combination of oxidative, abrasive, and adhesive wear, with significant material volatilization observed at 800 °C. ZrO₂ effectively mitigated abrasive scratching, suppressed surface adhesion, reduced oxidation, and inhibited molybdenum volatilization, thereby significantly improving wear performance. These findings provide new insights into grain refinement and oxide-mediated lubrication for developing advanced wear-resistant alloys.