A novel method for improving interfacial joining strength of vacuum brazed TiAl/GH3536 thin-walled structure by Au coating

Abstract

Lightweight components and materials based on the joining of dissimilar materials have attracted wide attention in aerospace field. To obtain the optimized micromorphology and interfacial microstructure of the brazed joints, a new method of Au layer deposition on TiAl base metal was proposed to assist the brazing of TiAl plate to GH3536 thin-walled structure. Significantly, the design of Au layer affected the brazing fillet, dissolution of GH3536 core and the evolution of interface, and then the maximum force under tensile loading of the hetero-thin-walled structure. The effect of Au layer thickness on the interfacial microstructure and mechanical properties was discussed in detail. Upon the deposition of an Au layer with a concentration of 0.2 wt% onto the TiAl plate, the load-bearing capacity of the brazed thin-walled structure was observed to undergo a significant enhancement. Specifically, the maximum force sustained under tensile loading was measured to be 391 N, thereby exhibiting a remarkable increase of 117 % relative to that of the Au-free system.