Wear resistance of TiN or AlTiN nanostructured Ni-based hardfacing by PTA under pin on disc test

In the present work, Ni-based metallic filler powders reinforced with TiN or AlTiN nanoparticles were deposited on D2-type tool steel by Plasma Transferred Arc (PTA). The mixes of TiN or AlTiN with Ni-based metallic filler powders were analyzed using technique of differential scanning calorimeter (DSC). The effect of tribological performance for Ni-based metallic filler powders with different amounts of TiN or AlTiN nanoparticles was studied. A pin on disc tribometer was used to evaluate the wear and friction behavior of the hardfacing under dry siding condition. The hardfacing were characterized by a scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), atomic force microscopy (AFM), roughness and nanoindentation tests. Results of DSC showed that the mixes of nanoparticles with metallic filler changed the dilution due to the high enthalpies of reaction. Microstructural results showed that the addition of TiN or AlTiN nanoparticles modified substantially the microstructure of the hardfacing, increasing the secondary hard phases and intermetallic content as well as the nanohardness. Moreover, as the TiN or AlTiN nanoparticles increased from 1 to 2 g and 2.4-3.4 g, the wear resistance of hardfacing increased four times that the D2 steel.