Brazing of tungsten based alloy/superalloy GH907 with lean Cu-Ag based fillers: Wetting, interfaces and performance evaluation

Vacuum brazing of tungsten based alloy and superalloy GH907 using lean Cu-Ag based fillers (CuAg30, CuAg30V0.2, CuAg30V0.4, wt%) at 1050 degrees C for 20 min was investigated. CuAg30V0.4 filler showed a maximum spreading area of 132.4 mm(2) and minimum contact angle of 15.94 degrees on tungsten based alloy during wetting process. The reduction of solid-liquid surface tension and the accelerated spreading rate driven by the diffusion of V atoms synergistically promoted the wettability and brazeability. Furthermore, the formation of (Fe, Ni) diffusion layer as well as Cu-rich infiltration zone seem to be responsible for high performance of joints, which exhibited 223.83 MPa of shear strength with V content of 0.4%.(c) 2020 Elsevier B.V. All rights reserved.

Automated summary

Vacuum brazing of tungsten based alloy and superalloy GH907 using lean Cu-Ag based fillers at 1050 degrees C for 20 min showed improved wettability and brazeability. The formation of (Fe, Ni) diffusion layer and Cu-rich infiltration zone contributed to the high performance of joints.