Study on the microstructure and mechanical properties of vacuum brazing titanium alloy using Ti-Zr-Cu-Ni amorphous filler metal

In this research, Ti-Zr-Cu-Ni quaternary amorphous alloys were used for brazing Ti-6Al-2Zr-1Mo-1V alloys below their beta-phase transformation temperature in order to obtain optimized mechanical properties. The microstructure and mechanical properties of Titanium alloys lap joints was investigated by scanning electron microscopy (SEM), X-ray diffractometer (XRD) and shear strength measurement. Experimental results show that holding time and brazing temperature are two key issues to the shear strength of the Titanium alloys lap joints. Furthermore, it was also found that Ti55Zr13Ni23Cu9 possessed the most outstanding shear strength under brazing temperature of 930°C and holding time of 10 min. The shear strength of brazing Ti45Zr34Ni8Cu13 was markedly improved under the conditions of rising the brazing temperature to 940°C and extending the holding time to 60min.