Thermal autofrettage of dissimilar material brazed joints

This paper presents a study on the effects of thermal autofrettage on the residual stresses in a Titanium-Copper brazed joint. It is shown that cryogenic thermal autofrettage has the potential to alter the residual stress field due to joining, in a manner that should result in an improvement in the subsequent operational fatigue performance of dissimilar material joints. Beneficial change in the residual stress field in the less-ductile component of the joint is apparent and desirable constitutive characteristics of the braze material to enhance the final residual stress field are also highlighted. Results from the finite element simulations are validated using experimental residual stress measurements produced using X-ray diffraction. The characteristics of the process and the findings of the work presented should also be relevant to dissimilar material joints manufactured by other processes.