Achieving high-strength W/W-10Cu joints by vacuum diffusion bonding with FeCoCu interlayer

To obtain W/W-10Cu joints with reliable interface bonding, the surface of the W plate was roughened by oxidation–reduction treatment, and the treated W plate was joined to W-10Cu by vacuum diffusion bonding with FeCoCu medium-entropy alloy as an interlayer. The effects of oxidation temperature on the microstructure and properties of the W/W-10Cu joints were investigated. The stability of the obtained W/W-10Cu joints under transient thermal loads was investigated through thermal shock tests. The results show that the surface of the W plate became rough and loose after oxidation–reduction treatment. The surface roughness (Sa) of the W oxidised at 900 °C and then reduced in H 2 at 850 °C was 1.833 μm. The W/W-10Cu joints prepared from this W had a maximum shear strength of 254.0 MPa, 60% higher than that of the W/W-10Cu joints prepared from untreated W (157.9 MPa). After 50 thermal shock tests at 600 °C–RT, the shear strength of the W/W-Cu joints prepared from the treated W oxidised at 900 °C was 111.6 MPa; the shear strength of the W/W-Cu joints prepared from untreated W was 42.7 MPa. This study provides an effective method for preparing high-strength W/W-10 Cu joints.