Effect of laser scanning speed on TiN/TiB–Ti based composite

In situ synthesised TiN and TiB particulate reinforced metal matrix composite coating was formed on Ti–3Al–2V alloy by laser cladding with a Ti/h-BN powder mixture. The phase structure, microstructure, microhardness and wear performance of the clad layer were analysed by optical microscope, X-ray diffraction, scanning electron microscopy, microhardness tester and wear testing machine. In situ TiN and TiB were synthesised in the forms of equiaxed crystal and needle platelet/whisker type microstructures in the clad layers. The scanning speed plays an important role on the microstructure of the TiN and TiB. The microhardness of laser clad layer was 850–1250 HV0·5, which was about five times of the substrate. The wear height loss of the substrate is almost two times of the clad layers.