Wear behaviour of HVOF thermally sprayed WC-14Co-3Cr coatings

The present study describes the tribological properties of thermal sprayed WC-14Co-3Cr (wt-%) coatings produced by using the high velocity oxyfuel (HV OF) deposition process. The coatings have been characterised with respect t o their chemical composition and microstructural features (SEM-EDX) and rou ghness (profilometry). Experiments using a tribometer (pin on disk configur ation) under non-lubricating conditions have been performed with the aim of determining the wear resistance of these coatings. To ensure reproducibili ty of the wear tests, the coated samples have been ground to an average sup erficial roughness R-a of 0.230 mum Steel balls of AISI 1086, 6 mm in diame ter were tested against coated and uncoated samples. The morphology of the wear tracks on bath pins and discs was characterised using SEM and three-di mensional profilometry. An average friction coefficient of 0.596 and averag e wear rate of 1.21 x 10(-4) mm(3) Nm(-1) were found for the tribological p air AISI 1086 pin/WC-14Co-3Cr coated disc. For this pair a mixed wear mecha nism of both abrasive and adhesive wear was observed far the pin with unidi rectional material transfer from the pin toward the coating. (C) 2000 IoM C ommunications Ltd..