Friction and Wear Behavior of AlTiN-Coated Carbide Balls Against SKD11 Hardened Steel at Elevated Temperatures

Abstract

In this study, AlTiN coatings were deposited on YT14 cemented carbide balls by arc ion plating technique. The friction and wear behavior of the AlTiN-coated balls against SKD11 hardened steel was investigated by sliding tests using a ball-on-disk tribometer at various temperatures from 25 to 700 °C in air. The results showed that the friction and wear behavior was significantly influenced by the testing temperature. Obvious fluctuations were observed in the friction curves at elevated temperatures, which could be attributed to the formation and rupture of unstable Fe and Cr oxide layers. As the temperature increased from 25 to 500 °C, the wear rate of the coated balls increased from the scale of 10−21–10−20 m3/N m, and then decreased to 10−22 m3/N m as the temperature further increased to 700 °C. It was also found that the friction and wear behavior of the coated balls was directly dependent on the counterpart materials. As the temperature increased, the main wear mechanism of the coated balls changed from mild abrasive wear and adhesive wear to abrasive wear failure at 500 °C, and then transferred to adhesive wear and mild oxidation wear at 700 °C. For SKD11 hardened steel, the primary wear mechanism changed from delamination wear to abrasive wear and then transferred to plastic deformation and fatigue wear, accompanied by adhesive wear and tribo-oxidation wear.