Development of high strength W/V/Au/ODS-Cu joint using HIP process

A new high strength bonding method between Tungsten (W) and Oxide Dispersion Strengthening copper (ODS-Cu) using vanadium (V) and gold (Au) inserts was investigated and the resulting joints were characterized with SEM, micro-hardness and four point bending test. For the joints using thick Au inserts (300 µm), a hardened reaction layer was observed in the V/Au interface region. On the other hand, the joints using thin Au inserts (0.7 µm) exhibited a serrated interface layer having homogeneous hardness profiles. In this case, the observed behavior is a reflection of degradation of melting point by inter-diffusion between Au and Cu. Room temperature bending test of the joints with and without 0.7 µm inserts at interface between V and ODS-Cu exhibited yielding behavior with the strength of approximately 300 MPa which is close to that of ODS-Cu. The joint with the thin Au insert had a serrated interface which implies appearance of liquid phase by reaction between Au and Cu.