The role of metal powder properties on the tribology of cold sprayed Ti6Al4V-TiC metal matrix composites

Ti6Al4V-TiC metal matrix composite (MMC) coatings were cold sprayed using spherical and irregular Ti6Al4V powders manufactured with plasma gas atomization the Armstrong process, respectively. Composite deposited showed higher ceramic retentions lower porosity compared to powder (SP) coatings. Sliding wear tests performed at two different normal loads a WC-Co ball as counterface. Wear test results that similar contents, composites exhibited abrasive mechanisms high coefficients of friction (CoF) rates. In (IP) composites, islands tribolayers, comprised fragmented TiC TiO 2 particles, resisted localized shear deformation leading low wear, free carbon from particles also lowered CoF. Increase in content IP MMCs 23% led coverage track area tribolayers further rate. At load, more continuous tribolayer, whereas no significant formation tribolayers. The highly tribolayer load (in MMC), extremely CoF (~ 0.25) other along Electron channel contrast imaging transmission electron microscopy analysis worn subsurface under coarse-grain microstructures bare regions (i.e. without coverage). coarser grain indicated less stress transfer both due hardness lubricating nature • on Composites better tribological performance. resistance depends cohesion between particles. Higher volume fraction facilitated for greater