Microstructure and tribological behavior of HVOF sprayed and laser treated CoCrTaAlCSiY coatings

Abstract

Co-based alloys are used over a wide range of application because of their excellent corrosion and wear properties. Especially the Stellites (Co-Cr-W) are well known and quite well researched. The CoCrTaAlCSiY is a new material on the field of thermal spray coatings and due to its composition was chosen for studding of tribological behavior. In this paper the HVOF sprayed and post heat treated coatings of CoCrTaAlCSiY are presented. Specimens were treated by a laser with two different laser parameters in order to reach different thickness of laser treated layers. Erosion test and linearly oscillating ball-on-flat test were applied to evaluate the wear behavior of CoCrTaAlCSiY coating. Microstructure of as-sprayed and heat treated coatings were also studied. The evaluation revealed a positive effect on wear coefficient for both laser treated coatings. A significant improvement of volume loss during erosion test was also observed for both laser treated coatings.