Microstructural and mechanical characterization of W/SiC bonding for structural material in fusion

The SiC/SiC composites are expected to be employed as structural materials in fusion reactors after DEMO. Tungsten may be used as armor material of divertor to protect from the high temperature heat flux. An advanced SiC/SiC composite, NITE SiC/SiC, has excellent resistance to high stress and temperature, and diffusion and sinter bonding methods using high temperature are able to join SiC/SiC composites. This work evaluates the microstructure of interphases when tungsten is joined to SiC to screen potential bonding techniques. The W/SiC joints were produced by diffusion bonding, sinter bonding and liquid phase sinter bonding methods using the hot-pressing methods. Evaluation by SEM, EPMA, TEM and shear test showed the promise of these bonding methods.