Microstructure and wear performance enhancement of carbon nanotubes reinforced composite coatings fabricated by laser cladding on titanium alloy

Carbon nanotubes (CNTs) reinforced composites were deposited on the TA2 titanium alloy by mean of a laser cladding (LC) of the Al3Ti-Cu-SiC-CNTs mixed powders, showing that huge amounts of the reinforced nanocrystalline phases/amorphous phases (APs) were fabricated in this coating; large amounts of the point defects were produced in the precipitates under an action of extreme high-temperature of a laser puddle; the mutual diffusion between C/Si can be achieved due to the similar atomic radii of them, forming APs. COF of this LC coating was in a range of 0.443 similar to 0.472, which was significantly lower than that of TA2 (0.562 similar to 0.581); considering that COF of this coating decreased significantly under actions of the Ti-Si-C compounds/CNTs due to self-lubricating effect, the reinforced phases in coating were beneficial to decrease COF due to the dispersion strengthening effect.