Microstructure evolution and mechanical properties of W/MA956 joints by brazing

Brazing experiments between tungsten and MA956 ODS steel were conducted at 1050 degrees C with different holding time to investigate the interface microstructure evolution and mechanical properties of the brazed joints. The interface microstructures were analyzed by the scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), and the mechanical properties of the joints were measured to find the optimal brazing parameter. The results show that tungsten and MA956 steel has been successfully joined by brazing. The intermetallic compound of Ni-W formed at the W/BNi-2 interface, which was detrimental to the strength of the joint. Due to the excellent mutual solubility between Fe and Ni, no new formed intermetallic compound was found at MA956-brazing filler interface. The shear strength of the brazed joints with BNi-2 filler reached 246 MPa at the optimal brazing parameter 1050 degrees C/20 min.