Influenceof Spraying Frequency on Tribological Property of 316L Steel Surface-Modified with Plasma Sprayed Mo-Al Coatings

The surfaces of 316 L stainless steel,an advanced automotive gear material,were modified with Mo-Al coatings,deposited by plasma spraying.The influence of the spraying frequency on the microstructures and tribological behavior was investigated with scanning electron microscopy(SEM) and multifunctional tribological tester.The results show that the spraying frequency had a major impact.To be specific,as the frequency increased from 5 Hz to 30 Hz,the compactness,uniformity and microstructures of Mo-Al coatings changed in an improvement-deterioration manner; the friction coefficient and wear rate varied in a decrease-increase mode.Plasma sprayed at an optimized frequency of 20 Hz,the lowest friction coefficient and wear rate were found to be 0.326 and 68.5,respectively; and quite a few uniform clusters,with contents resembling to those of Mo-Al coatings,were observed around the wear tracks on the fairly compact Mo-Al coatings.