Low-temperature direct diffusion bonding of hydrogenated TC4 alloy and GH3128 superalloy

Abstract Bonding at high temperatures can cause many problems, such as an induction of high stress, grain coarsening and strict requirements for bonding equipments, etc.. In this paper, a hydrogenation approach was utilized for the TC4 alloy before the dissimilar materials bonding process. Effects of hydrogen contents on the diffusion behavior of the TC4/GH3128 joints were investigated. Particularly, the mechanism that the hydrogenation affected the low-temperature bonding process of the TC4/GH3128 joints was discussed. By regulating the bonding temperatures, holding durations and hydrogen contents, a maximum of 92 MPa was achieved. The formation mechanism of the diffusion bonded TC4/GH3128 joint was proposed. This novel metal hydrogenation idea can offer new insights on the development of the low-temperature joining particularly suitable for dissimilar materials joining.