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. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.