Investigation of wear behaviour of HVOF sprayed WC-Co coatings for automotive parts in different working conditions

Reinforced metal matrix composite (MMC) hard coatings which are produced by thermal spray processes are used for various automotive parts such as piston rings and cylinder liners. Generally, WC-CoCr coatings are deposited by HVOF process for improving surface resistance of low alloyed steels. In this study, we examined the wear characteristics of WC-CoCr coatings on low alloyed steel substrate under different test conditions, using a sliding wear test unit with abrasive ball. Experimental studies discussed the effects of test load, temperature, work medium and sliding distance on the wear characteristics of coatings. Weight loss, wear track depth and width were observed. It was found that the weight loss of coatings increased in dry medium conditions. Wear weight loss was significantly reduced in lubricated condition due to decreasing friction. The wear track surface profile changed with lubrication and increasing temperature in test conditions. Under the base oil lubricated conditions the WC-CoCr coating performed well.