Comparative study on wear behavior of plasma sprayed Al2O3 coatings sliding against different counterparts

Although the friction and wear behavior of plasma sprayed aluminum matrix ceramic coatings have been extensively discussed in the last decades, only few researches have been carried out the wear mechanisms sliding against different pairs. The tribological behaviors of plasma sprayed Al2O3 coating sliding against ZrO2, Si3N4, Al2O3 and stainless steel balls in air were comparatively investigated in this study. It was showed that Al2O3 coating sliding against different counterparts exhibited diverse tribological behaviors, which could be mainly ascribed to the different mechanical properties of counterparts. Meanwhile, the tribochemical reactions influenced the friction performances significantly. Moreover, the transform of γ-Al2O3 to α-Al2O3 occurred during the friction, which was closely related to the coefficient of friction and thermal conductivities of counterparts. The main wear of Al2O3 coating sliding against ceramic materials resulted from the brittle fracture and abrasive wear. While it was dominated by adhesive wear when sliding against stainless steel, and accompanied with abrasive wear.