Effect of nano-Y2O3 on the microstructure and wear behaviour of TIG cladded TiC-Co-nY2O3 coating

Abstract

To improve the mechanical performance of Ti-6Al-4V alloy, TiC-Co-nY2O3 clad layer was deposited on Ti-6Al-4V alloy plate through TIG cladding route. Nano-Y2O3 powder in different weight percentages (n) was mixed with TiC-Co powder blend, and used as precursor. The microstructural analysis of the clad cross-section revealed the formation of uniform coating for incorporating nano-Y2O3. With the addition of nano-Y2O3, the melting efficiency of the precursor augmented, which utterly melted the TiC particles and transformed it into elongated dendrite during solidification. A marginal improvement in the average micro-hardness, along with significant reduction in the wear and coefficient of friction (COF) was observed for the addition of nano-Y2O3. Almost, four times lesser wear was recorded for TiC-Co-2%Y2O3 coating as compared to TiC-Co coating. The addition of nano-Y2O3 effectively refined the grain structure of the clad material, and improved the fracture toughness and ductility of the coating. Subsequently, the brittle cracking and extraction of TiC particles restrained during the sliding wear test, and augmented the absolute wear resistance of the cladding.