Effect of Plasma Spraying Parameters on Sliding Friction and Wear Behavior of Tantalum Coating

Ta coating was prepared by using plasma spraying technique.The effects of plasma spraying power and distance as well as powder feed rate on temperature and ve-locity of Ta particles during plasma spraying were investigated.The microstructure of the coating was analyzed by means of scan-ning electron microscopy.Moreover,the friction and wear behav-ior of the coating under dry sliding conditions was evaluated by using a ball-on-disc friction and wear tester.Results show that temperature and velocity of the in-flight Ta particles are highly dependent on spraying power and distance as well as powder feed rate.The optimized spraying power,spraying distance and pow-der feed rate were determined to be 36 kW,150 mm and 45 g/min respectively.Resultant Ta coating had dense structure and good wear resistance with a density of 15.2 g/cm3,hardness of 759 HV and tensile strength of 40 MPa and above.The Ta coat-ings obtained under different plasma spraying parameters had sim-ilar friction coefficient,and their sliding wear failure was domina-ted by fatigue-spalling.