Synthesis and sintering of SiC under high pressure and high temperature

Bhaumik, SK and Divakar, C and Ushadevi, S and Singh, AK (1999) Synthesis and sintering of SiC under high pressure and high temperature. Journal of Materials Research, 14 (3). pp. 906-911. ISSN 0884-2914

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    Abstract

    Starting from elemental powders, simultaneous synthesis and compaction of SiC were conducted at 3 GPa pressure and temperatures in the range 2100-2900 K. The sintered compacts were characterized by XRD, microhardness measurements, and microscopic studies. The efficiency of formation of SiC was dependent on the particle size of the silicon powder, crystallinity of the reactant carbon, molar ratio of silicon and carbon, and synthesis temperature and time. Carbon in excess of the stoichiometric amount was required to obtain compacts free from residual silicon. The SiC samples, with a Si:C molar ratio 1:1.05, prepared at 2100 K for 300 s, had a density and hardness of 3.21 g/cu cm (98.8 percent of theoretical density) and 22 GPa, respectively. The crystal structure of the SiC depended on the synthesis temperature. Pure beta-SiC in the temperature range 2100-2500 K, and a mixture of alpha- and beta-SiC above 2500 K were obtained. The beta-SiC was highly crystalline and nearly defect-free.

    Item Type: Journal Article
    Additional Information: Copyright for this article belongs to Materials Research Society
    Uncontrolled Keywords: Silicon carbide;Synthesis;Silicon;Reactions (chemical); Carbon;Powder blending;Reactive processing;Exothermic reactions;Sintering;Process parameters;Sintered compacts; Microstructure;Crystal structure;Phase ratio;Density; Hardness;Silicon carbides;Reactive sintering
    Subjects: CHEMISTRY AND MATERIALS > Nonmetallic Materials
    Division/Department: Materials Science Division, Materials Science Division, Materials Science Division, Materials Science Division
    Depositing User: M/S ICAST NAL
    Date Deposited: 20 Aug 2008
    Last Modified: 24 May 2010 09:51
    URI: http://nal-ir.nal.res.in/id/eprint/2925

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