Vacuum brazed joints of titanium alloy with low temperature filler metal

摘要

This study investigates, microstructure and mechanical properties of Titanium alloy brazed joint is performed in a vacuum furnace using low temperature filler metal. Microstructure of the brazed joints is analyzed by means of optical microscope, scanning electron microscope (SEM) and X-Ray diffraction (XRD). In addition, the mechanical strengths of the joints are evaluated by shear test and microhardness test. Brazing temperatures employed in this study are 720°C, 750°C, and 780°C for a holding time of 30 min. By increasing the brazing temperature, a variety of intermetallic phases are formed in the bond area, such as CuTi, Cu_2Ti, Mn_2Ti, MnZn_2, and AgTi solid solution. Both the brazing temperature and the brazing time are critical factors for controlling the microstructure and the better mechanical property of the brazed joints. The maximum shear strength of 154.15 MPa is achieved at 780°C and a holding time of 30 min.