A Tough, Thermally Conductive Silicon Carbide Composite with High Strength up to 1600°C in Air

Abstract

A sintered silicon carbide fiber-bonded ceramic, which consists of a highly ordered, close-packed structure of very fine hexagonal columnar fibers with a thin interfacial carbon layer between fibers, was synthesized by hot-pressing plied sheets of an amorphous silicon-aluminum-carbon-oxygen fiber prepared from an organosilicon polymer. The interior of the fiber element was composed of sintered beta-silicon carbide crystal without an obvious second phase at the grain boundary and triple points. This material showed high strength (over 600 megapascals in longitudinal direction), fibrous fracture behavior, excellent high-temperature properties (up to 1600 degreesC in air), and high thermal conductivity (even at temperatures over 1000 degreesC).

Low‐Temperature PECVD of Nanodevice‐Grade nc‐3C‐SiC

“…Below 250°C, no clearly resolved crystalline peaks can be observed. At T s = 250°C, however, a diffraction peak [5,6,16] at 2h = 35.7°emerges, indicating that 3C-SiC crystallites can be formed at such a low temperature. An increasing intensity of this diffraction peak at higher temperatures means that the crystal growth is enhanced.…”

“…[15][16] Moreover, limited growth rates and relatively low crystalline fraction in the available reports still remain major issues for potential uses of nc-3C-SiC in nanodevices. [15][16] High-quality SiC has commonly been synthesized at very high substrate temperatures typically exceeding 700°C, [5,10,17,18] which is at least a couple of hundred degrees higher than the requirements of the emerging sub-60 nm semiconductor technology. [19] Further reduction in feature sizes and interconnect layer thickness will demand even lower process temperatures largely unachievable by common thermal vapor deposition methods.…”

“…[1][2][3][4] A substantial lack of such synergy hampers nanodevice applications of nanocrystalline silicon carbide (nc-SiC) despite outstanding chemical, mechanical, optical, and thermal properties of bulk SiC. [5][6][7] Here we report a plasma-based synthesis of nanodevice-grade nc-3C-SiC films, with very high growth rates (7-9 nm min -1 ) at low and ULSI technology-compatible process temperatures (400-550°C), featuring: (i) high nanocrystalline fraction (67 % at 550°C); (ii) good chemical purity; (iii) excellent stoichiometry throughout the entire film; (iv) wide optical band gap (3.22-3.71 eV); (v) refractive index close to that of single-crystalline 3C-SiC; and (vi) clear, uniform, and defect-free Si-SiC interface. The counter-intuitive low SiC hydrogenation in a H 2 -rich plasma process is explained by hydrogen atom desorption-mediated crystallization.…”

Assessment of Silicon Carbide Composites for Advanced Salt-Cooled Reactors

“…SiC bonded fiber composite is commercially available as Tyrannohex™ from Ube Industries, LTd., Japan [9]. Tyrannohex™ is a potential alternative to SiC/SiC for various nuclear applications.…”

Joining of Cf/C and Cf/SiC Composites to Metals

“…Owing to the embedded carbon fibers, they have an excellent combination of mechanical properties. Therefore, C f /SiC composites are promising new structural materials for a variety of hightemperature burner environments, including hypersonic aircraft thermal structures, advanced rocket propulsion thrust chambers, cooled panels for nozzle ramps, turbo pump blisks/shaft attachments, and brake disks [Ishikawa et al, 1998]. Most such applications in aerospace and nuclear industry require joining CMCs to metals, ceramics or composites.…”