Studies on Inconel 625 and Al6061 bimetallic joints produced by CMT-based welding process

The current study focuses on metallurgically joining Inconel-625 and Aluminium-6061 materials, both essential in the aerospace industry, through the CMT-based welding process. The core objective of this work is to develop a novel solution for aerospace applications by combining the corrosion resistance and high strength properties of Inconel-625 with light weight and high thermal conductivity of Al6061, ultimately achieving enhanced thermal performance with reduced weight. The study uses CMT welding to overcome problems associated with conventional welding techniques for joining dissimilar metals, such as high heat input and intermetallic compound formation. The experimental process involves lap welding of Aluminium-6061 over Inconel-625 using CMT and CMT advance waveforms, by varying the welding speed and wire feed rate while the argon gas flow rate and filler wire diameter were kept constant. This article encompasses macrographic and micro-hardness analyses of the resultant weld joints, thereby demonstrating the feasibility of the process in producing bimetallic joints.