Microstructure characteristics of vacuum brazed joint for Mo-Cu alloy with 1Cr18Ni9Ti stainless steel

Mo-Cu alloy and 1Cr18Ni9Ti stainless steel were joined by vacuum brazing with Ag-Cu-Ti active filler metal at 910℃ for 20 min and a Mo-Cu/1Cr18Ni9Ti joint with a shear strength of 75 MPa was obtained. The microstructure and performance of Mo-Cu/1Cr18Ni9Ti joint were investigated by scanning electron microscope (SEM),energy dispersive spectrometer (EDS) and microhardness test. The results indicated that Ag-Cu eutectic and Cu-rich phase were produced in the brazed joint. There were few of TiC phases near the side of 1Cr18Ni9Ti stainless steel in the joint. The microhardness of brazed seam was lower than that of Mo-Cu alloy and 1Cr18Ni9Ti stainless steel. There are no brittle compounds formed in the Mo-Cu/1Cr18Ni9Ti joint. The shear fracture appearance shows shear dimple feature.