Wear Mechanisms Transition Map of the γ_N Phase under Dry Sliding against Si₃N₄ Ceramic Counterface

A single high-nitrogen face-centered-cubic (f.c.c.) phase (γ_N) layer was prepared by plasma source nitrided AISI 316 austenitic stainless steel. Tribological behavior of the γ_N phase layer against an Si₃N₄ ceramic counterface was investigated using a ball-on-disc tribometer under a normal load varying from 2 to 8 N and a sliding speed varying from 0.15 to 0.29 m/s without lubrication. Based on the detailed microanalyses for the worn surface and wear debris, the wear map of the γ_N phase layer was constructed under these experimental conditions using the response surface methodology. The results show that the oxidative wear was the main wear mechanism for the γ_N phase layer at the lower normal load. Nevertheless, the plastic deformation and the abrasive wear observed under the higher normal load.