Metallurgical aspect of a joint made of Inconel 718 and CuCrZr brazed with Ag-Cu eutectic filler

The realization of bimetallic structures is one the major challenges manufacturing industry, to this aim different technologies are employed, among these vacuum brazing presents some advantages: technology, in fact, relatively easy use and relative low temperature process time avoid formation brittle intermetallics thermally affected zones. An application technology regenerative thrust chamber for rocket engines where cooling channels CuCrZr joined Inconel 718 combustion chamber. In work critical metallurgical aspects occurring during using eutectic Ag-Cu filler described detail. These include two distinct zones inside an interdiffusion zone with Kirkendall porosity at interface 718-Brazing Alloy. analysis fracture surface after tensile tests indicates that weak point joint.