Residual Stress Distributions in Dissimilar Titanium Alloy Diffusion Bonds Produced From Powder Using Field-Assisted Sintering Technology (FAST-DB)

Abstract

The conventional approach when engineering components manufactured from titanium is to design the thermomechanical processing to develop an optimal microstructure in a single alloy. However, this conventional approach can lead to unnecessary over-engineering of components, particularly when only a specific subcomponent region is under demanding service stresses and environments. One approach being developed to join multiple alloys in a single component and enhance engineering performance and efficiency is FAST-DB—whereby multiple alloys in powder form are diffusion bonded (DB) using field-assisted sintering technology (FAST). But the joining of multiple alloys using conventional welding and joining techniques can generate high residual stress in the bond region that can affect the mechanical performance of the components. In this study, the residual stress distribution across dissimilar titanium alloy diffusion bonds, processed from powder using FAST, were measured using X-Ray diffraction and the Contour method.