Tribological Behavior of a Shot-Peened Nickel-Based Single Crystal Superalloy at High Temperature

Abstract

The tribological behavior of a nickel-based single crystal superalloy treated by shot-peening has been investigated. Friction tests under three normal loads and three temperatures were carried out based on the ball-on-disk configuration. The results showed that coefficient of friction (COF) and wear rate of the shot-peened nickel-based single crystal superalloy (SP-NBSC) at room temperature were nearly 2 times and 4 times that at 600 ℃, respectively. However, there were no significant differences in COF and wear rate between the SP-NBSC superalloy and the as-received NBSC superalloy, which was ascribed to the competing effects between the increased hardness and roughness of the SP-NBSC superalloy. High-temperature friction promoted the formation of a glaze-layer on the substrate, which was derived from the sintering and compacting of the wear debris. The formed glaze-layer prevented the direct contact of the friction pair and contributed to the reduced COF and wear rate. The wear mechanism of the SP-NBSC superalloy at high temperature including oxidation, adhesion, and abrasion. With the decreasing normal load and increasing temperature, the adhesive wear weakened. This work provided insights into the effects of shot-peening treatment on the tribological properties of the NBSC superalloy.Graphical Abstract