Tribological performance of Ni-Fe-Al2O3 multilayer coatings deposited by pulse electrodeposition

This study was conducted to investigate the wear behavior of electrodeposited Ni-Fe-Al2O3 coating and to assess the effect of its multilayer (ML) structure. The ML Ni-Fe-Al2O3 coatings were deposited by frequent changing of duty cycle between two values of 90% and 20%. The matrix of alternative layers contained 28 and 54 wt% Fe corresponding to the duty cycles of 90% and 20% respectively, with embedded Al2O3 nanoparticles. The thickness of each layer in ML coatings was in the range of 0.08-4 μm. The decrease in thickness of layers improved the hardness via Hall-Petch strengthening mechanism. The dry ball-on-disk test showed that wear behavior of Ni-Fe-Al2O3 coatings had a transition from mild to severe wear at 10 N. The wear mechanism was abrasive in the mild regime while with increasing the applied load plastic deformation and delamination were dominant mechanisms. The lower layer thickness in ML coating led to the higher hardness and wear resistance.