Microstructure and Mechanical Properties of B₄C/TC4 Joints Brazed with AgCuTi+W Composite Brazing Material

In this study, the surface of boron carbide (B₄C) ceramics was metallized, and a composite solder material system, AgCuTi-W, containing tungsten (W) particles, was utilized to join B₄C ceramics and TC4 titanium alloy. It was found that at a soldering temperature of 880 °C and a holding time of 10 min, the joint interface exhibited dense bonding without visible micropores or cracks, and dispersed white particle-like W was distributed throughout the weld zone. With the addition of 5 wt% W, the microstructure of the intermediate layer became refined, providing more nucleation sites for solid solution, resulting in a denser structure. However, as the W content increased to 7 wt%, the flowability of the solder material decreased, leading to a decline in mechanical properties. The highest shear strength of 75 MPa was achieved when employing the AgCuTi-5wt%W+AgCu foil composite solder material system for bonding at 880 °C.