MICROSCOPIC MORPHOLOGY AND MICROSTRUCTURE OF Ti-N AND Ti-Ni PHASE BETWEEN THE DILUTION ZONE AND THE CLAD ZONE IN LASER REMELTING NiCrBSi/TiN LAYER ON Ti-6Al-4V ALLOY SURFACE

Abstract

The microscopic morphology and microstructure of Ti - N and Ti - Ni phase between the dilution zone and the clad zone in laser remelting NiCrBSi / TiN layer on a Ti - 6Al - 4V alloy were characterized using TEM and SEM. The experimental results showed that during laser irradiation heating, TiN particles were partially dissolved into the melted Ni -base alloy, and the dissolved Ti and N atoms were precipitated in the form of TiN , TiN 0.3. Ti exhibits height activity, it combines with Ni forming Ti 2 Ni , TiNi matrix intermetallic during laser remelting, faults exist in the Ti 2 Ni and TiNi phase, and crystal lattice of TiNi phase is superlattice. Lastly, the cause of the formation of the Ti - N and Ti - Ni phase is discussed.