<p>This study examined the impact of replacing Inconel 738 powder with Amdry 718 as a high-melting-temperature powder (HMTP), and varying content (40, 50, and 60 wt.%) of BNi-2 as low-melting-temperature brazing powder (LMTP) on the microstructure and creep resistance of wide-gap-brazed Inconel 738 joints. The lower Ti content of Amdry 718 helps prevent the formation of Ti–rich eutectic phases that compromise creep resistance at elevated temperatures. A thermal cycle, consisting of three stages of brazing, diffusion, and aging, was employed. For the 60% LMTP sample, solidification included three steps, in which γ-phase, Cr_xB_y (Cr-rich boride), and a ternary eutectic (consisting of γ, Cr-rich boride, and Ni-rich boride) were formed. With the reduction of the LMTP content from 60 to 40%, the amount of ternary eutectic decreased due to the lack of boron. SEM images indicated that the dissolution of γ՛ corners occurred during the diffusion stage, resulting in the formation of Al- and Ti-enriched regions in the base metal. These regions subsequently served as nucleation sites for secondary γ՛ precipitation during the aging stage. While the elemental distribution within precipitates changes during aging heat treatment, their overall morphology remains largely unaffected. However, increasing the LMTP value from 40 to 60% improved the fluidity of the brazing filler, which reduced porosity from 7.5 to 1.7%. This improvement led to significant enhancement in rupture time from 1 to 3h. Moreover, fractographic analysis on the aged samples reveals a ductile fracture mode.</p>