Structure, mechanical, and tribological properties of Ag2CrO4 high-temperature oxide coatings

Abstract

In this research, a series of Ag₂CrO₄ high-temperature self-lubricating oxide coatings were prepared by reactive radio frequency magnetron sputtering under different argon-oxygen flow ratio (Ar:O₂ ratio) conditions. Effects of the gas flow ratio on phase composition, coating morphology, high temperature treatment in air atmosphere, mechanical and tribological properties are studied. A low Ar:O₂ flow ratio is beneficial for the formation of Ag₂CrO₄ phase. At high temperature treatment, formation of surface Ag particle and volatility and decomposition of the Ag₂CrO₄ phase are observed, and the volatility and decomposition of the coating are slight at temperatures below 500 °C. When the Ar:O₂ ratio is 1:1, the coating shows exceptional comprehensive performance, it is dense with a smooth surface, excellent toughness and bond strength, and the lowest wear rate and coefficient of friction, which is 0.14 mm³/10⁻³N∙m and 0.35 respectively. The coating can function as a lubricant in temperature environments of 500 ℃ and below, demonstrating practical application value.