Microstructural Characteristics of Wire Arc Additive Manufacturing with Inconel 625 by Super-TIG Welding

Nowadays, the implementation of additive manufacturing (AM) is rapidly growing in various sectors. Many manufacturing industries are demanding an increase in the size of the AM parts. Wire arc additive manufacturing (WAAM) offers a high deposition rate and quality products without size limits. The welding process of gas tungsten arc welding is widely used for WAAM. This paper introduces the WAAM process using Super-TIG welding by Inconel 625. Super-TIG welding is a kind of TIG welding process using C-Filler. The high deposition rate of WAAM can be obtained using Super-TIG welding to build large-scale components. The productivity of Super-TIG welding is higher than in conventional TIG welding. The layering strategies have been developed to refine the microstructure of the WAAM parts. The deposits of the single-pass beads with oscillation have resulted in the formation of larger grains with epitaxial grain growth. However, the multi-pass beads with stringer and zig-zag layering sequences have refined the microstructure with the presence of smaller grains. The influence of heat input on the WAAM properties along with layering strategies has also been observed.