Mechanical properties of HIP bonded W and Cu-alloys joint for plasma facing components

Hot isostatic pressing (HIP) bonding technology of W (tungsten) and Cu-alloys have been developed to fabricate plasma facing components of the fusion reactor. As regards W and oxygen free high conductivity copper (OFHC-Cu), the highest bonding strength was achieved at the HIP condition of 1273 K×2 h×147 MPa. On the other hand, W and dispersion strengthened copper (DS-Cu) were not bonded directly because of tungsten oxide production at the bonding interface. In this study, HIP bonding tests on W and DS-Cu with OFHC-Cu disk and/or Au-foil were performed. Bonding tests with OFHC-Cu disk were successfully bonded and it is shown that thickness of OFHC-Cu disk over 1.0 mm may be needed and the tensile strength are a little higher than that of HIP treated OFHC-Cu. Bonding tests with Au-foil were also performed and successfully bonded. Au-foil lead to an improvement in bonding strength and a lowering of bonding temperature.