Improvement of Microstructure and Mechanical Properties of Powder Coating on Ti-6al-4 v Alloy with Different Rare Earth Metals Using Tig Cladding

The purpose of this research is to enhance the microstructure and mechanical characteristics of powder coating on grade V Ti-6Al-4 V alloy using tungsten inert gas (TIG) cladding with various rare earth metals (RE). Ti-6Al-4 V alloy is a widely used material in various industries. The coating was produced by blending powders including grade V titanium alloy (Ti-6Al-4 V), tungsten carbides (WC), aluminum nitrate (ALN), nickel (Ni), and different rare earth metal oxides (CeO2 and La2O3) in a fixed ratio and then applied to the surface of Ti-6Al-4 V alloy using TIG cladding. Variable currents (300A, 400A, 500A, and 85A) of various samples were used to examine the microstructure and mechanical characteristics of coatings. The observation of the result showed that the microstructure and grains of the samples depend upon different rare earth metal oxides as well as varying currents. A refined columnar grain microstructure was formed for all the samples containing RE’s oxides, and short columnar grains and microneedle-type appearances were formed without RE’s oxides. Due to varying currents, the uniform distribution of fine columnar grains had a hexagonal structure, and equiaxed grains were formed that enhanced the mechanical characteristics of titanium alloy such that the sample has a microhardness between 500 and 870 HV0.5 with RE oxides and 368 HV0.5 without RE oxides.