Microstructure Evolution and Mechanical Performance of W-Niti Composite Coating Produced on Ti-6Al-4V Titanium Alloy by TIG Cladding Method

Abstract

Ti-6Al-4V alloy is one of the most promising alloys which is used in automobile manufacturing, biomedical application, chemical industries, and aerospace industries. It has very impressive properties like high specific strength, good corrosion resistance, low density and biocompatibility. However, it has some limitation like low hardness, poor wear resistance, low fatigue strength which restrict its usage in many other applications. In this work, an attempt has been taken to improve the mechanical and surface properties of Ti-6Al-4V alloys through surface cladding with the coating materials of NiTi-W where tungsten powder is reinforced with NiTi powder mixture by TIG arc as heat source. The microstructural evolution during the surface alloying of titanium alloy was analyzed through SEM images of the alloyed layer and XRD analysis. The mechanical properties i.e. micro-hardness and sliding wear characteristic was assessed by Vickers microindentation method and pin-on-disc type wear test respectively. It was found that a uniform clad layer was formed on the titanium alloy. The clad layer exhibit hardness value up to 700 HV and wear resistances also improved compare to the substrate materials.