Effect of heat treatment into tensile strength, hardness and microstructural attributes of TIG welded Ti-6Al-4V titanium alloy

ABSTRACT

The present work deals with heat treatment of tungsten inert gas (TIG)-welded Ti-6Al-4 V alloy plates. Four welded plates were taken under study. Three plates were heat-treated and one plate was kept in ‘as welded’ condition. The heating temperature was 1050°C for a holding time of 20 min. After heating, these three welded plates were cooled at three different media like water, sand and air. The tensile strength and hardness of the heat-treated samples and the ‘as welded’ sample were measured by using universal testing machine and Rockwell hardness tester, respectively. Also, the microstructures of all the samples were observed by using optical microscope. Three different types of microstructures of Ti alloy, Bi-modal, martensite and Widmanstätten, were observed in this study. Due to possessing Bi-modal structure, ‘as welded’ specimen showed a good combination of ultimate tensile strength (UTS), hardness and ductility. The martensitic structure had made the water-quenched specimen stronger and harder than ‘as welded’ specimen. The sand-cooled sample had both Widmanstätten and Bi-modal structure. It showed the least hardness among all samples. Air-cooled specimen had mainly contained Widmanstätten microstructure with high value of UTS and moderate hardness.

KEYWORDS:

• Ti-6Al-4V alloy
• heat treatment
• tensile strength
• microstructure

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There is no data set associated with the paper.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Saurabh Dewangan

Dr Saurabh Dewangan is working as an Assistant Professor in the Department of Mechanical Engineering, Manipal University Jaipur, India.