1782 Journalof the American Ceramic Society--Seo and Koumoto Vol. 79. No. 7 Fig 9. SEM photographs of p-SiC particles synthesized with heating rate of (a)0.5"C/min and(b)14" C/min. 1420C for 30 min with heating rates of (a)0.5 References (b)14 C/min. Since the sizes of the synthesized particles hardly Koumoto. M. Shimohigoshi, S. Takeda, and H and Thermoelectric Energy Comversion in Porous Si stacking fault density had little to do with a size Ceramic Socicty, Westerville, OH, 1989. change in the heating rate would affect the rate of G. Sasaki, K. Hiraga, M. Hirabayashi, K. Nihara, and T. Hirai, "Microstruc between the Sio gas and the carbon because of the ture around Indentation of Chemical Vapor Deposition Observed by Transmis- ates of Sio gas st hence stacking fault formation must Microscopy, "Yogyo Kyokaishi, 94, 779-83(1986 have been affected by the manner in which the Sic formed L. U. Ogbuji, T, E. Mitchell, and A. H. Heuer, "The B-a Transformation in The surface energy of the (1111 planes was much smaller olycrystalline SiC: Ill. The Thickening of a Plate, "J Am. Ceram Soc.,64, 91 than those of the other crystal planes. If atoms could be added continuously to the (111) planes, the crystal might easily grow S Seo, C.H. Pai. K. Kournoto, and H. Yanagida in the Phase Transformation of SiC J. Ceram Soc. Jpn, 100, 227-32(1992) in the [lll] direction, and stacking faults would form easily in 3. G. Lee and I.B. Cutler. "Formation of Silicon Carbide from Rice Hulls, the 111 planes in order to decrease the formation energy for Am. Ceran.Soc.Bm,.54[2]195-98(19 B-SiC. Moreover, under rapid reaction conditions, newly added oS.R. Nutt, "Microstructure and Growth Model for Rice- Hull-Derived SiC ous B-SiC Fabricated from Rice Hull Ash, J. pn,1017814-18(1993) IV. Conclusions d Factors affecting stacking fault formation during the syn- hesis of B-SiC powder by carbothermal reduction were inves- Doctoral thesis, pp 9-28. University of Tokyo, 1992. tigated. The fol ng conclusions can be drawn from the W.S. Seo, C. H. Pai, K. Koumoto, and H. Yanagi present study Development and Stacking Fault Annihilation in B-Sic The formed B-SiC usually exhibited two major morpholo gies, whiskers and spherical particles. The whiskers, with a Wssn4pm,9417(191) high density of stacking faults, formed perpendicular to the (7(10993) and Grain Growth in Porous Ceramics of B-SiC, ". Mater Res,8 cal particles, on the other hand, had a low density of stacking faults, and were formed by a solid-solid reaction. The soli bon; the solid-solid reaction took plac to as reaction occurred directly between Sio gas and solid car g: Thomas. w:. 6 103-11 (9 - ay Powder Profile Refinement Method Ceram Sot ell and H. M. Otte lectron Diffrac- ween solid Si and tion Patterns from Thin Platelets "Phys. Status Solidi, 12, 5366(1965 via a disproportionation reaction of gaseous Sio into Si M. Pickard and B. Derby, "TEM of Silicon Carbide Whisker O,.The average size of both whiskers and spherical Microstructures, "J Mater: Sci., 26, 6207-17(1991) particles increased with increasing reaction temperature and IL. Wang, H. Wada, and L F Allar esis and Characterization of sic time, although their stacking fault contents, measured by XRD, Whiskers ". Mater Res, 7[11 148-63(1 ppeared to decrease, possibly because of a size effect. Increas G.CWei"Beta SiC Powders Produced by Carbothermic Reduction Silica in a High-Temperature Rotary Furnace. "J. Am. Ceram. Soc., 62[7 ing the heating rate up to the reaction temperature greatly enhanced stacking fault formation. sV. D. Krstic, "Production of Fine, High-Purity Beta Silicon Carbide Pow Acknowledgment in Nagoya University for TEM Photo Mr, S. Arai of IMV E. Givargizov; Pp. 136-43 in Growth of Crystals; Vol. 11. Edited by A.A Chernov, translated by J E S. Bradley. Consultants Bu New Yorl