Effect of Mo content on tribological properties of atmospheric plasma-sprayed Mo-NiCrBSi composite coatings under dry and oil-lubricated conditions

摘要

NiCrBSi is a material generally used in wear-resistant coatings. In order to improve the tribological properties of atmospheric plasma-sprayed NiCrBSi coatings. Molybdenum (Mo) was incorporated into the NiCrBSi coatings to reduce the friction coefficient and wear rate under dry and oil-lubricated conditions. In this paper, Mo-NiCrBSi composite coatings with Mo content of 5, 10, 20 and 30 wt.% were deposited on stainless steel substrates respectively by atmospheric plasma spray. X-ray diffraction, optical microscopy and scanning electron microscopy equipped with energy dispersive spectroscopy were utilized to investigate the phase structure and surface morphology of the composite coatings. Reciprocating friction tests were conducted to measure the friction coefficients and 3D optical microscopy was used to depict the wear track profiles. The results showed that the 30 wt.% Mo-NiCrBSi coating exhibits the best tribological performance. In addition, MoO_2 and MoS_2 films were formed in the friction process under dry condition and oil-lubricated condition respectively.