Evaluation of interface strength between metal and ceramics to be utilized for development of fusion reactor components

Yttrium oxide coating was successfully made on V–4Cr–4Ti–Y alloy using DC-sputter coating followed by heat treatment at 1000 °C. Adhesive shear strength of the yttrium oxide coating was evaluated by means of scratch tests. The Weibull analysis of the shear strength of the interface between the coating and alloy made by DC-sputter coating indicated that surface polishing affects the evaluation of the strength. In the case of the same surface roughness about 0.1 μm, it was noted that small additions of yttrium to V–4Cr–4Ti would improve adhesive property of the interface between yttrium oxide coating and vanadium alloys. Yttrium oxide formed at the very beginning of the coating process could result in better adhesive properties.