Microstructure and mechanical properties of Inconel-625 slab component fabricated by wire arc additive manufacturing

ABSTRACT

Wire arc additive manufacturing is a promising reliable free-form fabrication technique suitable for producing large-scale components that feature a very low buy-to-fly ratio. This research work is aimed to fabricate a rectangular prototype Inconel-625 alloy slab using a robotic metal inert gas welding system. The microstructure and mechanical properties of as-deposited and solution-annealed (SA) alloys were investigated. It was found that the as-deposited alloy exhibited a columnar dendritic structure and the presence of intermetallic phases such as the Laves phase, NbC and carbides were observed in the gamma-nickel matrix. In SA deposit, the intermetallic phases were dissolved in the NiCr-matrix and the secondary carbides M₂₃C₆, M₆C were also observed in the microstructure. It was found that the ultimate tensile strength and microhardness of the as-deposited alloy were higher than that of SA deposit.

KEYWORDS:

• Wire arc additive manufacturing
• microstructure characterisation
• HRTEM
• X-ray diffraction (XRD) and mechanical properties

Acknowledgements

The authors gratefully acknowledge M/s. Schlumberger-Cameron Manufacturing India Pvt. Ltd., Coimbatore, India, for providing material for this work. The authors are thankful to the management of M/s. Coimbatore Institute of Technology, Coimbatore, India, for providing all necessary facilities to carry out this work. The authors are also thankful to M/s. Indian Institute of Science, AFMM Laboratory, Bangalore, for their help in the EPMA work.

Disclosure statement

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