Formation mechanism and wear behavior of gradient nanostructured Inconel 625 alloy

The formation mechanism and wear behavior of a gradient nanostructured (GNS) Inconel 625 alloy were investigated using SEM, TEM ball-on-disc sliding tester. results show that surface mechanical grinding treatment (SMGT) induced an approximately 800 μm-deep microstructure, consisting nano-grained, nano-laminated, nano-twined, severely deformed layers, which resulted in reduced micro-hardness from 6.95 GPa (topmost surface) to 2.77 (coarse-grained matrix). nano-grained layer the high-density nano-twins subsequent interaction between dislocations. width depth scar, loss volume, rate SMGT-treated sample smaller than those untreated coarse-grained sample. Moreover, mechanisms for both samples mainly abrasive adhesive wear, accompanied with mild oxidation wear. notable resistance enhancement GNS was attributed high micro-hardness, residual compressive stress, strain capacity layer.