Dissimilar Brazing of Ti–15Mo–5Zr–3Al and Commercially Pure Titanium Using Ti–Cu–Ni Foil

Abstract

Dissimilar brazing of Ti–15Mo–5Zr–3Al (Ti-1553) to commercially pure titanium (CP-Ti) using Ti–15Cu–15Ni foil was performed in this work. The microstructures in different sites of the brazed joint showed distinct morphologies, which resulted from the distributions of Mo, Cu, and Ni. In the brazed zone adhered to the Ti-1553 substrate, the partitioning of Mo from the Ti-1553 into the molten braze caused the formation of stabilized β-Ti without Ti2Cu/Ti2Ni precipitates. In the CP-Ti side, the brazed joint displayed a predominantly lamellar structure, composed of the elongated primary α-Ti and β-transformed eutectoid. The decrease in the Mo concentration in the brazed zone caused the eutectoid transformation of β-Ti to Ti2Cu + α-Ti in that zone. The diffusion of Cu and Ni from the molten braze into the CP-Ti accounted for the precipitation of Ti2Cu/Ti2Ni in the transformed zone therein. The variation in the shear strength of the joints was related to the amount and distribution of brittle Ti2Ni compounds. Prolonging the brazing time, the wider transformed zone, consisting of coarse elongated CP-Ti interspersed with sparse Ti2Ni precipitates, was responsible for the improved shear strength of the joint.

Dissimilar joining of Titanium alloy to Aluminium using Al-Si based filler alloy by vacuum brazing technique

“…It was concluded that strength of the joint primarily depends on the microstructure formed in the brazing zone and the formation of intermetallics in the joint area. β-Titanium alloy (Ti-15Mo-5Zr-3Al) was brazed to commercial pure Titanium by Gui-Lin Yue et al 19 using Ti-Cu-Ni filler alloy foil. It was done at 1243 K for different brazing time durations of 3, 30 and 60 min, respectively.…”

“…Researchers have experimented with brazing commercial Titanium and Titanium alloys using Ti-based filler metals 19,20 . It was concluded that strength of the joint primarily depends on the microstructure formed in the brazing zone and the formation of intermetallics in the joint area.…”