Tribological Properties of Spark Plasma Sintering TZ3Y20A–SrMoO₄ Composites at Elevated Temperature

The chemical precipitation method was employed to prepare uniform spherical SrMoO₄ powders. The ZrO₂ (3 mol% Y₂O₃)–20 wt% Al₂O₃ (TZ3Y20A) matrix composites incorporating SrMoO₄ were fabricated by spark plasma sintering, and their tribological properties were tested under dry sliding against Al₂O₃ balls from room temperature to 800 °C. Compared with TZ3Y20A ceramic, TZ3Y20A–20 wt% SrMoO₄ composite has lower friction coefficients of 0.26–0.55 from room temperature to 800 °C. The wear rates are of the order of 10⁻⁷ mm³/(Nm) at room temperature and 200 °C and 10⁻⁵–10⁻⁴ mm³/(Nm) at 400, 600, and 800 °C. The lubricating film consisting mainly of SrMoO₄, which spreads on the worn tracks during sliding progress, plays a critical role in the improvement in the tribological properties of the composites.