Diffusion Welding of Fe-base Heat-resistant Alloy A286 with Transient Liquid Phase Interlayer

Abstract

The diffusion weldability of Fe-base heat-resistant alloy A286 with such interlayers as isothermally-solidificating after transiently-melting have been studied by microscopy, electron-probe-microanalysis, tensile tests and stress-rupture tests of the joints. The liquid phase diffusion weldability between dissimilar alloys of Fe-base A286 and Ni-base Inconel 713C was also investigated.
It was found more difficult to diffusion weld Fe-base A286 with transient liquid phase Ni-base interlayer including only boron for lowering the melting point of the interlayer than to diffusion weld Ni-base superalloys, because of the poor melting effect of the interlayer for Fe-base alloys. However, strong void-free joints of A286 were produced with the interlayer including both boron and silicon which moderately melted the base metal surfaces at the joint interface. With this interlayer, it was also found possible to diffusion weld Fe-base A286 to Ni-base Inconel 713C.