Effect of Brazing Temperature on Microstructure and Mechanical Properties of TC4 Titanium Alloy Vacuum Brazing Joint

TC4 titanium alloy was brazed in vacuum with Ti Zr CuNiSi amorphous brazing filler metal, the microstructure and mechanical properties were analyzed by using X-ray diffraction（XRD）, scanning electron microscopy（SEM）, energy dispersive spectroscopy（EDS） and compression shear tester. The results show that the weld is composed of reaction layer and filler metal layer, the reaction layer mainly contains α-Ti and β-Ti phases, and the filler metal layer is mainly rich Ti-Zr phase.With the increase of the brazing temperature, the thickness of the reaction layer increases, while the thickness of the solder layer decreases. At 980 ℃, the filler metal layer nearly disappears, while the α+β Ti phases almost fill the weld. The shear strength of the joint also increases with the increase of the temperature. The the shear strength is the maximum of 437 MPa at980 ℃, and the fractures all occur at the weld.