Friction and Wear Characteristics of BaCr2O4 Ceramics at Elevated Temperatures in Sliding Against Sintered Alumina Ball

In this article, friction and wear characteristics of BaCr₂O₄ ceramics have been investigated using a high-temperature friction and wear tester from room temperature to 800?°C in dry sliding against sintered alumina ball. At room temperature, the friction coefficient and wear rate of BaCr₂O₄ ceramics are quite high. BaCr₂O₄ ceramics exhibit low friction coefficients and small wear rates with temperature increasing up to 400?C600?°C. The oxidation reaction of BaCr₂O₄ during high-temperature wear tests is responsible for the tribological properties. The oxidized product of BaCr₂O₄ is BaCrO₄, which forms a smooth self-lubricating film on the worn surface to effectively reduce friction and wear. However, at 800?°C, severe oxidation reduces the relative density of sintered BaCr₂O₄ ceramics, and further expedites the materials removal process.