Hf-doped amorphous filler metal towards high-performance TC4/SS316L brazed joints

Conventional welding poses significant challenges when directly joining titanium alloys and stainless steels due to their inherent physical and metallurgical properties variances. The primary challenge in achieving durable joints is to avoid the formation of brittle Ti–Fe intermetallic compounds (IMCs). In this study, Hf-doped amorphous filler material was employed to join TC4/SS316L dissimilar metals by vacuum brazing, achieving a maximum shear strength of 380 MPa under 910 °C/10 min at 1.25 at.% Hf. The interfacial microstructures consisted of the sequence: β-Ti/α-Ti/β-Ti + Ti 2 (Cu, Ni)/Ti 2 (Cu, Ni)/Ti 2 (Zr, Ni)+TiCu/Ti 2 (Ni, Cu, Fe)/γ-(Fe, Ni) + σ. This study presents a successful approach for the brazing of titanium alloy with stainless-steel alloy for high-precision components in the field of aerospace and nuclear sectors.