Effect of Tempering on the Microstructure and Mechanical Performance of Laser Deposited Stellite 12-TiN-Sn Mixed Composite on TC17
F-H. Shan, S-L. Gong, J. Tao and J. Yang
The influence of tempering on the microstructures and wear properties of laser deposited Stellite 12-TiN-Sn mixed composite on TC17 Ti-alloy substrate is investigated in detail. Laser deposited of the Stellite 12-TiNSn mixed powders on a substrate can form the nanocrystals reinforced hard composites, which increased the wear resistance of the substrate surface greatly. Experimental results indicated that lots of the amorphous and nanocrystalline phases were produced in such composites; indeed, the Ti3Sn nanocrystals that appeared at the intersplat region, and these lattice values were very compatible to d-space of the Ti3Sn compound at an orientation of (201). After the tempering process, the uniform and fine compact composites were obtained, and the microhardness also increased accordingly. The tempering led the plastic and toughness properties of such composites to be improved greatly, so the hard ceramics were hard to be peeled off during the dry sliding wear process, improving the wear resistance. The research on laser induced nanocrystalline composites provides essential theoretical and experimental basis to promote the development of the laser technologies.
Keywords: Fibre laser, Stellite, titanium, alloy, powder, composite, laser deposition, tempering, wear, microhardness, microstructure, nanocrystal