Oxygen-free copper and pre-metalized graphite were brazed using CuNiSnP braze alloy by high frequency induction heating method. Interracial microstructures and reaction phases were analyzed by scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDS）. The strength and resistance of the joints were tested. It is found that when the brazing parameters are optimized, the structures of the joints are graphite/（Cu,Ni）/Ni（s.s）＋NixPy/Cu3P＋Cu（s.s） （including Sn）＋eutectic structures （Cu3P＋Ni3P＋Cu（s.s）/Cu （s.s）/Cu）. When the temperature increases to 750℃ or the holding time prolongs to 300 s, the eutectie structures disappear and the amount of Cu3P increases. The maximum shear strength of the joints is 5.2 MPa, which fracture at the interface of graphite and metallization. The resistance of the joints is no more than 5 mΩ.
A kind of self-made AgCuTiSn braze alloy powder was used to join graphite and copper. The whole brazing process was performed under vacuum circumstances at different temperatures （ 1 033 - 1 193 K） for several holding time （300 - 1 800 s ）. According to scanning electron microscope （SEM）, energy dispersive spectrometer （EDS） and electron probe X-ray microanalysis （ EPMA ） results, the reaction products of the interface are TiC, Ti3Sn, Cu（s. s）, Ag（s. s） and Cu-Sn compound. As the brazing parameters increase, the quantity of Ag（ s. s） in the braze alloy and C fibers on graphite/AgCuTiSn interface reduce, while that of Cu （ s. s） in the braze alloy improves. When the brazing temperature /s 1 093 K and holding time is 900 s, the joint can obtain the maximum room temperature shear strength 24 MPa.
Vacuum brazing of SiO2 glass ceramic and TC4 alloy using a commercially available TiZrNiCu foil was investigated. The interfacial microstructure and the fractures were examined with an optical microscope （OM） and an S-4700 scanning electron microscope （SEM） equipped with an energy dispersive spectrometer （EDS） and an electron probe X-ray microanalyzer （EPMA）. The structure of joint interface was identified by XRD （JDX-3530M）. Meanwhile, the fracture paths of the joints were comprehensively studied. The results show that processing parameters, especially the brazing temperature, have a significant effect on the microstructure and mechanical properties of joints. The typical interface structure is SiO2/Ti2O＋Zr3Si2＋Ti5Si3/（Ti,Zr）＋Ti2O＋ TiZrNiCu/Ti（s.s）/TiZrNiCu＋Ti（s.s）＋Ti2（Cu,Ni）/TC4 from SiO2 glass ceramic to TC4 alloy side. Based on the mechanical property tests, the joints brazed at 880 ℃ for 5 rain has the maximum shear strength of 23 MPa.
