Microstructure and mechanical properties of TC4 joints brazed with Ti–Zr–Cu–Sn amorphous filler alloy

Abstract

The Ti51.44Zr16.26Cu30Sn2.3 (at%) amorphous filler alloy in a ribbon form was prepared by melt spinning. The Ti–6Al–4V alloy was brazed in vacuum furnace by using the Ti51.44Zr16.26Cu30Sn2.3 amorphous filler alloy. The effects of brazing temperature and holding time on the interfacial microstructure and mechanical properties of the Ti–6Al–4V brazed joints were investigated. The brazed joints are composed of α-Ti, β-Ti, and (Ti, Zr)2Cu phases. The shear strength of the joints increases with brazing temperature increasing from 1153 to 1193 K and holding time from 10 to 15 min, while decreases with brazing temperature and time further increasing. Low temperature brazing results in the formation of microcracks and voids in the seams, which are harmful for the shear strength of the joints. In the joint brazed at 1193 K for 15 min, a fine α + β Widmanstatten structure beneficial to the mechanical property is formed, and the joint exhibits relatively high joint strength of 180 MPa.