Synthesis of Silver Free Eutectic Alloys for Be and Cu<sub>99.32</sub>Cr<sub>0.6</sub>Zr<sub>0.08</sub> Brazing

Abstract

Silver free Ti-43at.%Cu (Ti-Cu) eutectic alloy have been developed for the brazing of Be and Cu99.32Cr0.6Zr0.08 (CuCrZr). The structural and microstructural properties of the as obtained alloys were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS). The analysis have revealed that the Cu-Ti eutectic alloy have a fine and homogeneous eutectic structure with the phase composition corresponding to the Ti-Cu phase diagram. These observations are consistent with the thermal properties of the alloys determined by DTA-TG analysis. The role of Mn on the eutectic structure, as well on the wetability properties was also studied. The effect of Mn is to produce a less coarse eutectic structure and to decrease the wetability angle. The mechanical testing of CuCrZr/Ti-Cu/CuCrZr junctions have demonstrated that these alloys are suitable for the brazing of Be and CuCrZr. The shear strength of the CuCrZr/TiCuMn/ CuCrZr increases with Mn concentration reaching the value of about 280 MPa for 2at% Mn.