Tensile Strength Evaluation of Polycrystalline SiC Fibers

TEM/EELS Characterization of a Sintered Polycrystalline Silicon Carbide Fiber

“…The SiC crystals are from 0.5 to 3 m large with a mean size 24 It fits almost exactly the optimum microstructure designed with a model proposed by Srinivasan and Venkateswaran on the basis of a processing-microstructure-property correlation. 23 Conversely, the SiC mean grain size of the fiber is slightly larger than that of the SiC powder (i.e., less than 1 m) used to process the fiber, 31 the difference being possibly due to some grain growth during the sintering of the green fiber beyond 2000°C. Furthermore, and as shown in Fig.…”

“…A faceted surface has been also reported from SEM images by Giannuzzi et al, 24 and by Srinivasan and Venkateswaran. 23 Therefore, it can be considered that the left and bottom sides of the splinter image shown in Fig. 2 are actually part of the external surface of the fiber.…”

“…22,23 Although such fibers (developmental fibers from Carborundum, USA) exhibit a relatively low tensile strength owing to the large SiC-grain size, they are one of the best reinforcements in terms of thermal stability and creep resistance. 24,25 The aim of the present contribution is to depict the composition and structure of these fibers manufactured by Carborundum Co. on the basis of TEM/EELS data.…”

“…A totally different route to near-stoichiometric SiC fibers is based on the extrusion of a mixture of SiC powder (␣-or ␤-SiC) with various spinning additives and sintering aids (including boron) followed by sintering at very high temperatures (2000-2300°C). 22,23 Although such fibers (developmental fibers from Carborundum, USA) exhibit a relatively low tensile strength owing to the large SiC-grain size, they are one of the best reinforcements in terms of thermal stability and creep resistance. 24,25 The aim of the present contribution is to depict the composition and structure of these fibers manufactured by Carborundum Co. on the basis of TEM/EELS data.…”

Effect of Hydrogen Atmosphere on Pyrolysis of Cured Polycarbosilane Fibers

“…Several methods of preparing silicon carbide fibers with a stoichiometric composition have been tried using various fabrication processes such as CVD (chemical vapor deposition), 10 powder sintering, 11,12 CVR (chemical vapor reaction), 13,14 and preceramic polymer pyrolysis processes. 18 -27 At present, SiC fibers produced by CVD, powder sintering, or CVR processes seem to have some disadvantages in diameter and strength.…”