Study on the damage evolution of fretting wear in an Inconel 718 laser cladding alloy layer at different temperatures

In this study, Inconel 718 alloy samples were prepared by laser cladding deposition technology, and GCr15 steel balls were selected as the friction pair. The tangential fretting wear tests were conducted in ball-on-flat point contact mode using a self-developed multifunctional fretting wear tester. The damage evolution law of fretting damage with the number of cycles for laser cladding Inconel 718 alloy was investigated at room temperature (RT) and 400 °C. The obtained results reveal that the coefficient of friction curves and energy dissipation value in the process of fretting wear first increased, then decreased, and finally reached a stable state with increasing cycles. At room temperature, the fretting running states gradually changed from mixed slip regime (MSR) to gross slip regime (GSR). There was clear spalling in the fretting damage zone, and a large mass of wear debris was formed on the worn surface. As the test time continued, the width and depth of the wear marks gradually increased, the volume of material wear increased, and the wear damage of the material gradually aggravated. When the test temperature was 400 °C, the fretting was running in the MSR. As the number of cycles increased, spalling and adhesion of wear debris occurred in the fretting damage zone. The main mechanisms of fretting wear were oxidation wear, abrasive wear, fatigue wear and adhesive wear.