Pulsed solid-state laser welding of Ti6Al4V/Ni80Cr20 alloys: interfacial microstructure and mechanical performance

The reliable joining of Ti6Al4V and Ni80Cr20 alloys is significant for aerospace applications due to the demanding service environments. Traditional joining methods, such as diffusion bonding, though widely employed, are unsuitable for micro-repair tasks due to the excessive processing times which hinders their applicability in high-precision, small-scale aerospace component maintenance. In this study, an ultrahigh-strength Ti6Al4V/Ni80Cr20 joint was explored using pulsed Nd: YAG laser. An investigation was conducted to evaluate the effects of laser pulse duration and beam diameter on the microstructure and mechanical properties of the joints. The microstructure was characterised. The interface includes AlNi 3 + NiTi, α-Ti + NiTi, and α-Ti + NiTi + Ni 3 V. The joint can achieve the maximum shear strength of 286.47 MPa and microhardness of 462.40 Vickers hardness under the pulse duration of 1.6 ms and the beam diameter of 1.0 mm, both exceeding those of the Ni80Cr20 alloy. These findings underscore the advantages of pulsed laser welding, particularly improved joint reliability, operational efficiency, and environmental sustainability. Overall, this work provides valuable insights into the fundamental mechanisms governing pulsed laser welding of dissimilar titanium/nickel alloys, offering a promising foundation for the development of micro-welding technologies tailored for precision repair in aerospace components.