THE INFLUENCE OF LINEAR VELOCITY ON THE WEAR BEHAVIOR OF THERMAL SPRAYED COATINGS UNDER DYNAMIC ABRASION TEST CONDITIONS

Surface coatings applied by a high-velocity oxy fuel (HVOF) thermal sp ray process were subjected to a newly developed dynamic abrasion test. The test consists of combined impact and abrasion. Impact of samples with a round nose stylus was conducted at two specified linear velocit ies. The wear rates corresponding with the linear velocities were reco rded and compared for a number of test cycles. Different substrate mat erials were used for the test and a number of coating thicknesses were examined. Uncoated samples were subjected to identical tests. Unlike many wear test processes currently in use, the wear test developed and used here is severe and fast acting, making it suitable for thick coa tings and situations involving combined wear. The results of the wear tests show the effects of the linear velocity prior to impact on the s urfaces in term of material loss and crater depth caused by dynamic we ar testing. The influence of rebound following impact, combined with t he linear velocity of the reciprocating stylus, has a major effect on the wear rates of the samples tested. (C) 1997 Elsevier Science S.A.