Electron Microscopy and Microanalysis of the Fiber–Matrix Interface in Monolithic Silicone Carbide‐Based Ceramic Composite Material for Use in a Fusion Reactor Application

Abstract

A composite material made from continuous monolithic silicone carbide (SiC) fibers and a SiC-based matrix (SiC(f)/SiC), was prepared using a novel technique, i.e. adapted dip coating and infiltration of SiC fibers with a water suspension containing SiC particles and a sintering additive. This kind of material could be used in the first-wall blanket of a future fusion reactor. Using magnetron sputtering, the SiC fibers were coated with various thin layers (TiC, CrN, CrC, WC, DLC-diamond-like carbon) of the interface material by physical vapor deposition (PVD). Using scanning and transmission electron microscopy and microanalysis, detailed microstructural studies of the fiber-matrix interface were performed. Both samples, with coated and uncoated fibers, were examined under a load. The microcracks introduced by the Vickers indenter continued their path through the fibers, and thus caused the failure of the composite material, in the case of the uncoated fibers or deviated from their primary direction at the fiber-matrix interface in the case of the coated fibers.

Fabrication of CNT-SiC/SiC composites by electrophoretic deposition

“…The SiC fabric was pre-treated with a sodium dioctyl-sulfosuccinate (SDOSS) solution to improve wettability. 41 After the deposition, the samples were dried in air at room temperature, vacuum-infiltrated by an aluminium dihydrogen phosphate (Al(H 2 PO 4 ) 3 ) aqueous solution (TKI Hrastnik, Slovenia), and sintered at 1300 • C in argon (Ar) for 3 h. The microstructures of the green and sintered samples were observed using field emission gun scanning electron microscopes (FEG-SEM, LEO 1525, and Zeiss SUPRA 35VP). The sintered samples were inspected by EDS.…”

“…As reported elsewhere, [40][41][42]44 SiC powder can be deposited either from ethanol or water. However, higher ZP values can be obtained in aqueous suspensions, resulting in deposits with higher particle packing density.…”

Electrophoretic deposition in the production of SiC/SiC composites for fusion reactor applications

“…Before deposition the SiC-fabrics were rinsed with acetone and distilled water or pre-treated with a sodium dioctyl-sulfosuccinate (SDOSS) solution. 20 The progress of the deposition was monitored by the change in the current. The bulk deposits were evaluated in terms of the final weight and the solids content, while the degree of particle packing was assessed with a scanning electron microscope.…”

Densification of a SiC-matrix by electrophoretic deposition and polymer infiltration and pyrolysis process

“…7,8 In addition, the sintering aids increase the activation of the material, 9 which negates one of the main advantages of SiC f /SiC composites in comparison to steels. Therefore, attempts have focused on the development of so-called hybrid routes, which combine different fabrication techniques in order to achieve a dense material without jeopardizing the advantageous properties of the pure SiC.…”