Characterization of Ti600 Ti-Alloy Surfaces Modified by Laser-Cladding of SKD11 Wire

Ti600 Ti-alloy,an advanced aerospace engine material,was surface-modified by laser cladding of SKD11 wire.The influence of the wire feed-rate,laser power and scanning speed on the microstructures and surface hardness was investigated with scanning electron microscopy and energy dispersive spectroscopy.The results show that the optimized laser cladding conditions included:a laser-power of 200 W,a scanning rate of 1.4 mm/s and a wire feed-rate of 5 mm/s.The equiaxial grains,columnar grains and cellular grains occupied,respectively,the top,middle and bottom of the clad-layer; laminar martensite and some austenite dentrites coexisted in the heat-affected zone(HAZ).The hardness,varying in 720~910 HV range,followed a descending order:clad layer>HAZ-layer>Ti600 Ti-alloy,possibly because of formation of Cr-carbide and V-carbide.We suggest that laser cladding of SKD11 wire be feasible for repairing of macroscopic damages on surfaces of Ti600 Ti-alloy.