Friction surface evolution of Ni-based superalloy with addition of revert at high temperature

Two types of superalloys, one containing 60 % revert and the other without revert, were dry-sliding tested to study the friction surface evolution behavior at 730 °C for 1, 15, 30 and 60 min respectively. Results show that adding revert contributes to higher wear-resistance and suppression of undersurface crack formation. The wear mechanism transitions from predominantly abrasive-adhesive wear to oxidative-adhesive wear over time. A sudden drop (about 40 %) in friction coefficient occurs within the initial 2.5 min. The oxide layer is discontinuous after 1 min of sliding test. After 15 min, a more fully developed oxide layer was observed, along with the enrichment of Al, Cr, and Ti. The wear debris undergoes repeated compaction and sintering, leading to the formation of a dense oxide layer. As the continuously sliding and compaction for 30/60 min, an internal oxide layer and an outer dense glaze-like structure are sequentially formed on the friction surface of sample with revert.