Tribological Properties of Spark-Plasma-Sintered ZrO2(Y2O3)–Al2O3–Ba x Sr1−x SO4 (x = 0.25, 0.5, 0.75) Composites at Elevated Temperature

Abstract

Self-lubricating ZrO 2 (Y 2 O 3 )-Al 2 O 3 -Ba x Sr 1-x SO 4 (x = 0.25, 0.5, 0.75) composites have been fabricated by spark plasma sintering (SPS) method. The tribological properties have been evaluated using a high-temperature friction and wear tester at room temperature and 760°C in dry sliding against alumina ball. The composites exhibit distinct improvements in effectively reducing friction and wear, as compared to the unmodified ZrO 2 (Y 2 O 3 )-Al 2 O 3 ceramics. The ZrO 2 (Y 2 O 3 )-Al 2 O 3 -Ba x Sr 1-x SO 4 (x = 0.25, 0.5, 0.75) composites have great low and stable friction coefficients of less than 0.15 and wear rates in the order of 10 -6 mm 3 /Nm at 760°C. Delamination is considered as the dominating wear mechanism of the composites at room temperature. At elevated temperature, the formation and effective spreading of Ba x Sr 1-x SO 4 (x = 0.25, 0.5, 0.75) lubricating films during sliding play an important role in the reduction of the friction and wear.

Microstructure and High-Temperature Wear Performance of FeCr Matrix Self-Lubricating Composites from Room Temperature to 800 °C

“…The CuAlO 2 formed a soft surface layer which could reduce friction coefficients. Ba 0.25 Sr 0.75 SO 4 showed a good lubricating effect in Fe 3 Al alloys [20,21]. Ba 0.25 Sr 0.75 SO 4 softened and formed a lubricating film on the contact surfaces at elevated temperatures.…”