Inconel 718 合金钎焊研究进展

Inconel 718 alloy is a key precipitation-strengthened nickel-based superalloy used in aerospace and energy power fields. The fabrication and in-service repair of precision components, such as aero-engine turbine blades and combustors, highly depend on brazing technology. The surface oxide film of the alloy easily leads to poor wettability of brazing fillers, and the thermal cycle during brazing tends to cause base metal softening and stress cracking, bringing great challenges to the design of brazing fillers and process control. This paper focuses on three core problems in the brazing of Inconel 718 alloy: wettability, base metal softening, and stress cracking, analyzing their mechanisms and improvement strategies. It systematically summarizes the composition, metallurgical behavior, and selection criteria of nickel-based and precious metal-based brazing filler systems. It clarifies the influence of brazing parameters such as temperature, holding time, and joint gap on the microstructure and properties of joints, as well as the performance strengthening mechanism of post-brazing heat treatment, and looks forward to the future development direction of Inconel 718 alloy brazing technology.