Microstructure and residual stress at diffusion bonded interface between vanadium and Ti-6Al-4V

Dissimilar metal joining is increasingly important for a variety of technological applications, including aerospace, automotive, and medical fields for example. The advanced manufacturing methods that enable efficient production of multi-material parts often leave complex residual stress states that lead to geometric distortion or part failure. In this work, microstructure and composition are investigated around a dissimilar metal interface between V and Ti-6Al-4 V alloy formed by vacuum diffusion bonding. Microstructural and compositional analyses are completed with electron backscatter diffraction and energy dispersive spectroscopy, where multiple microstructural regions are found at the bonding interface. Residual stresses across the interface are characterized by surface sensitive techniques, either measuring stress locally or globally. Cross-correlation electron backscatter diffraction, nanoindentation, and X-ray diffraction were used here, which provide valuable insight into the residual stress profile. The complex microstructures and compositional gradients found across this dissimilar metal interface ultimately affect how the sample interacts with a reference specimen, complicating quantitative analyses.