Influence of Natural Serpentine on Tribological Performance of Phosphate Bonded Solid Coatings

Natural serpentine powders as functional fillers were incorporated to promote the anti-wear performance of phosphate-bonded solid coatings. Optimal mass percent of natural serpentine in phosphate coatings was first explored. Thereafter, to further stimulate strengthening effect of natural serpentine on tribological performance of phosphate composite coatings, harsher friction condition on the phosphate composite coatings was conducted. The experimental result indicated that the optimal incorporation of natural serpentine in phosphate coatings was 10 wt.%, through which anti-wear performance of phosphate coatings was significantly elevated. Additionally, accompanied by the increase of applied load and sliding speed, natural serpentine was gradually activated, and interfacial interactions between naturals serpentine and counterface were intensified. As a result, a continuous protective tribo-film was in situ formed on the counterface, through which serious furrows generated on the counterface were effectively self-repaired during the friction process. What’s more, further abrasion on both phosphate composite coatings and counterface was also greatly restrained. Graphical Abstract Natural serpentine as the enhanced phase was incorporated into phosphate bonded solid coatings. The experimental results indicated that when applied load and sliding speed were increased, transfer and adhesion of phosphate composite coatings on the counterface were apparently intensified, and simultaneously, serious furrows generated on the wear spot were obviously reduced. What’s more, a continuous tribo-film was in-situ formed on the counterface, through which the direct abrasion between phosphate composite coatings and counterpart steel ball was restrained, and therefore, the anti-wear performance of phosphate composite coatings was significantly promoted.