助剤無漆加炭化ケイ素のHIP焼結(4.固相反応法)(<特集>新技術によるセラミックスの合成と評価(II))

概要

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Eight kinds of commercial SiC powders were cold pressed isostatically, encapsulated in a silica glass tube, and HIPed in 150MPa-argon gas at 1900°-2000°C. The density, microstructure, hardness and KIC were studied. The results are summarized as follows:(1) The density of sintered specimens depends strongly on the mean particle size of starting powders and HIP temperature. High density (>99.7% T. D.) was obtained by HIPing above 1950°C using powders with the mean particle size less than 0.6μm. With 0.8μm α-SiC powder, the sintered density was about 95% T. D. with slight dependence on the HIP temperature.(2) The microstructure of highly dense sintered materials was uniform with fine grains, but that of 95% T. D. material was characterized by coarse grains and intra-granular isolated pores.(3) α-SiC powder sinters better than β-SiC powder for the same mean particle size.(4) Fine SiC powders gave high Vickers hardness and low KIC value in comparison to coarse powders.
社団法人日本セラミックス協会の論文
1987-02-01