Diffusion Brazing of Copper Beryllium Using Ag-15.5Cu-16.5Zn-18Cd As Interlayer

Transient liquid-phase diffusion bonding was employed to join copper-beryllium in this work, at first spreading test was employed with different silver base and copper base interlayers. The process was carried out at two temperatures under argon atmosphere. Results illustrate that Bag 1a (Ag-15.5Cu-16.5Zn-18Cd) is the best choice for brazing copper beryllium. Zn spread preferentially and affected on wetting of BAg7 interlayer. The bonding process was carried out at a temperature range 0f 650-800 Celsius degree for 15 minutes and various times under argon atmosphere. Interfacial microstructures were examined by Light Microscopy (LM), Scanning Electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Microhardness, tensile tests were used for evaluating the mechanical properties. Maximum tensile strength of 100 Mpa was obtained for bonds processed at 750 Celsius degree without Heat treatment and 170 Mpa with Heat treatment. Eutectic with varied with time and temperature. Results showed that it was four micron in temperature of 800 Celsius degree for 15 minutes and it reached zero in 750 Celsius degree 30 minutes. Also in this work the joint strength were evaluated by peel test. Intermetallic phases at the joint interface and the peeled surfaces were examined using scanning electron microscopy (SEM). In general, raising the annealing temperature and time increases the joint stress.