Effects of solid lubricant and laser surface texturing on tribological behaviors of atmospheric plasma sprayed Al2O3-ZrO2 composite coatings

Atmospheric plasma-sprayed (APS), low-friction Al2O3-ZrO2 coatings were deposited with solid lubricants, and their effects on the laser surface texturing (LST) under a lubricated condition (commercial engine oil, 5W30) were evaluated. All specimens showed a 19.6% dimple density, and the contact angle of the APS coatings after LST processing decreased by ∼19-50%. The hydrophilicity of the APS coatings improved after LST processing, and the tribological behaviors of the APS coating containing different solid lubricants were mainly observed in the abrasive grooves, spalling, microcracks, residual pores and trapped wear debris on the worn surface. The coefficient of friction for the APS coatings was affected by the solid lubricants and the LST processing. The coefficient of friction for the APS coatings (except for h-BN) when adding solid lubricants and LST processing decreased to 3.7-7.9% and 2.3-9.5%, respectively.