Investigation of enhancing surface hardness in Ti-6Al-4V alloy by TIG welding

摘要: Department of Materials Science and Engineering, Majlesi Branch, Islamic Azad University, Isfahan, Iran. Abstract. The Ti-6Al-4V alloy is the most important and widely used titanium alloy which enjoys the welding, forging and machining capabilities. For this reason, it has extensive usage in automobile and military applications. Moreover, this alloy has the capability of being heat treated in order to reach a maximum strength up to 165 Ksi. But, one of its disadvantages is the low hardenability. In this regard, this paper investigates the increase of surface hardness by TIG welding. For this purpose, all the samples were investigated using optical microscope after casting. Also the phase detection was done by XRD method. The results show that with a 75A continuous current, the fully Martensitic microstructure is obtained with a Vickers hardness as high as 600.