Brazing Ti-48Al-2Nb-2Cr Alloys with Cu-Based Amorphous Alloy Filler

In this work, the Ti-48Al-2Nb-2Cr (at. %) alloy was successfully brazed using a Cu-based amorphous filler in 600 s under varied brazing temperatures. The element diffusion, microstructure, and precipitation phase of the joints are analyzed in detail, and the formation schemes are discussed. Reaction products in the joints are found as AlCuTi, Ti2Al, -Ti, and (Ti,Zr)(2)(Cu,Ni). The interfacial microstructures varied subjected to the brazing temperature, while the shear strength of the joint firstly increased, and then accordingly decreased. The maximum shear strength of 266 MPa was reached under a brazing temperature of 1213 K and a holding time of 600 s. A formation mechanism was proposed to explain the shear strength variation following the width and amount of brittle compounds in the interfacial reaction layer.