Fabrication of Ti10Fe5Si5Cr3Nb Composite Coatings on Ti-6Al-4V Alloy using Laser Cladding Technique

Abstract

Ti10Fe5Si5Cr3Nb composite coatings were fabricated using laser cladding technique. Laser power was varied from 800W to 1200W while the scanning speed was kept constant at 1.5 m/min. The microstructural analysis of the samples was conducted by using optical microscope, X-ray diffractometer and scanning electron microscope coupled with energy dispersive spectroscopy. Potentiodynamic polarization and diamond indenter were used to study the corrosion and microhardness properties of the alloy. The alloy exhibited a dendritic microstructure with Si-rich dispersed phase. Grain coarsening was observed to be dependent on coating depth. The microhardness was high at the top and decreased with coating depth. No improvement in corrosion resistance was noticed but the presence of Cr in the alloy promoted passivation.

Keywords:
Laser metal deposition; substrate heating; composite coating; microstructure; microhardness