Analysis on SP700/TC4 titanium alloy honeycomb sandwich brazing

SP700/TC4 titanium alloy honeycomb sandwich construction is brazed by amorphous foil solder Ti-Zr-Cu-Ni. The effect of brazing temperature and holding time on microstructure of brazing interface and mechanical property has been researched. The results show that when the brazing temperature varies in the range from 875 ℃ to 890 ℃，with the increasing of the temperature, diffusion of the elements as well as the tensile strength of the weld could be better. When brazed at 890 ℃ with the holding time ranging from 2 h to 4 h, the tensile strength of the weld increases at first, and reaches the optimum with 3.5 h holding time, then decreases gradually. The optimized brazing technology is 890 ℃/3.5 h, with which the average tensile strength, three point bending strength, compression strength and L/W shear strength are 14.64, 224.05, 11.21, 4.43 and 3.76 MPa respectively, and the weak part is TC4 honeycomb core.