Effect of process parameters on the microstructure evolution and wear property of the laser cladding coatings on Ti-6Al-4V alloy

In this paper, Co-based composite coatings were fabricated by laser cladding Co42 + B4C mixed powders on Ti-6Al-4V titanium alloy. The comprehensive effects of laser power and scanning velocity on the microstructure evolution and wear property of the laser cladding coatings were studied. Results indicated that the coatings were mainly comprised of gamma-Co/Ni, TiC, TiB2, TiB, NiTi, CoTi, CoTi2, and Cr7C3. With the decreasing of laser specific energy (from 12.7 kJ cm(-2) to 4.9 kJ cm(-2)), the TiC dendrites and TiB particles were refined. Compared with the Ti-6Al-4V titanium alloy, the microhardness and wear resistance of the composite coatings were enhanced obviously. Lower laser specific energy led to higher microhardness and better wear resistance owing to more TiB2 bulks distributed in the cladding coating. (C) 2016 Elsevier B.V. All rights reserved.