To investigate the effect of surface roughness on the fretting wear behavior of the Inconel 718 alloy, specimens fabricated by selective laser melting (SLM) were polished using SiC abrasive papers to obtain different surface roughness levels. Ball-on-flat tangential fretting tests were conducted under a normal load of 50 N, displacement amplitudes of 50 and 100 µm, and a total of 104 cycles. The results reveal that all test conditions fall within the gross slip regime (GSR). The coefficient of friction was not significantly affected by surface roughness, while the energy dissipation per cycle exhibited a decreasing trend with decreasing roughness. The high-roughness surface (Ra = 0.80 µm) exhibited severe stress concentration, leading to asperity fracture and fatigue delamination. The medium-roughness specimen (Ra = 0.43 µm) developed a dense third-body layer, showing a synergistic mechanism of abrasive and fatigue wear. The low-roughness specimen (Ra = 0.07 µm) maintained a stable contact interface with sufficient debris evacuation, dominated by adhesive and abrasive wear. At a displacement amplitude of D = 100 µm, the wear depth reached −6 µm, indicating the largest material removal and the most severe damage.
Wang et al. (Wed,) studied this question.