ABSTRACT
The joining of thin sheet Ti-6Al-4V alloy has potential application as an encapsulation of miniature components. However, it is quite challenging to achieve a defect-free joint in a fusion welding process since the complexity increases many folds with reduced thickness of the materials. In the present investigation, thin sheet Ti-6Al-4V alloy is welded under different process parameters (26, 45, and 74 J/mm), using a controlled and regulated pulse laser welding technique. The weld joints are further analysed using an experimental and numerical approach to explore the interplay of thermal-microstructural and mechanical characteristics. The outcome of the present investigation reveals better surface quality, desirable microstructural changes, and enhanced joint strength for the joints fabricated under the least heat input condition (26 J/mm). Such overall improvement in the joint characteristics is associated with the high value of cooling rate (2834 K/s), leading to the formation of fine needle-shaped α’-martensite, which corresponds to maximum joint efficiency of 90%. Surface finish is another crucial factor that is affected by the amount of heat input. Joints fabricated under low heat input conditions (26 J/mm) exhibits a lower roughness value (Ra~5.67 µm) as compared to joints fabricated under high heat input conditions (74 J/mm).
Acknowledgements
The present investigation is a result of research carried out at the Indian Institute of Technology Guwahati (IIT Guwahati), Assam. The authors gratefully acknowledge the experimental facility provided by the Department of Mechanical Engineering, Central Workshop, and Central Instruments Facility (CIF) of IIT Guwahati, Assam.
Disclosure statement
No potential conflict of interest was reported by the author(s).