Dry Sliding Friction and Wear Performance of HVOF Sprayed WC–Co Coatings Deposited on Aluminium Alloy

The tribological behaviour of WC–Co Cermet coatings coated on Al6061 alloy was studied in this work. WC–Co Cermet coatings have been coated with different thicknesses by changing the amount of the cobalt using HVOF (High velocity oxy fuel technique). The coatings produced have been subjected to microhardness, friction and wear testing. A disc and pin type machine has been used for assessing friction and wears characteristics. The influence on tribological performance of coating thickness and cobalt levels was examined and compared with aluminium alloy. WC–Co coating enhanced hardness by 34% and 42% in 100 and 200 micron thicknesses respectively, compared to aluminium alloy. The wear rate and the coefficient of friction are decreased by 48 and 12%, respectively, compared to uncoated aluminium alloy. Both coatings and substrates increase their wear rate and friction coefficient (COF) with the increase in load and sliding speed. Scanning Electron and Confocal microscopy examinations of worn surfaces were carried out to evaluate coating wear processes.