Advances in welding of titanium and its alloys using CMT, MIG, and laser-MIG hybrid processes: A comprehensive review

The need to weld Titanium (Ti) and its alloys is becoming more important in relation to aerospace, medical, and naval industries that require light yet strong structures. The present common fusion process of Ti alloys, however, is limited because it is hampered by issues arising from oxidation, grain coarsening, and porosity. The objective of this paper is to summarize recent findings in relation to Cold Metal Transfer (CMT), Metal Inert Gas (MIG), or Laser-MIG (LAMIG) methodologies used in Ti and its alloys. The CMT and pulse CMT (CMT+P) process supports low heat input with improved microstructures that are achieved by governing droplet transference. The addition of minor oxidative components to gas shielding during welding arc enhancement and improved weld hardness supports improved weld properties. The addition of high-intensity laser processing to groove-assisted weld control in MIG supports improved defect-free welds in relation to strength and ductility. The output parameters include the weld parameters that are directly related to the factors of porosity and plasma stability. The analysis reveals that the hybrid approach is better than conventional methods for enhancing key parameters related to properties. Correlations between process, microstructure, and properties are presented in this work for use in aerospace industries. • CMT enables ultra-low heat input welding of titanium with refined microstructure and minimal distortion • Pulsed and assisted MIG welding improves arc stability and mechanical performance of titanium joints • Laser–MIG hybrid welding achieves superior strength–ductility balance with significant porosity reduction • Hybrid welding processes outperform conventional methods for aerospace-grade titanium applications