Mg還元テルミット法によるHfCの微粉末合成と生成過程

概要

論文の詳細を見る
rights: 社団法人日本セラミックス協会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110002290316/The preparation conditions and formation process of HfC fine powders from HfO_2 by Mg-thermite method were examined under a CH_4 flow. HfC fine powders of single phase were successfully prepared by heating powder mixtures of Mg and HfO_2 with molar ratio of 4 and 5 at 800゜-950℃ for 1 h in a 25-100 vol% CH_4 flow. The formation process of HfC powders was as follows: (1)HfO_2+2Mg→α-Hf+_2MgO, (2)3CH_4+2Mg→Mg_2C_3+6H_2, (3)Mg_2C_3→2Mg+3C, (4)α-Hf+xC+y/2H_2→HfC_xH_y and (5)HfC_xH_y+(1-x)C→HfC+y/2H_2. Where, the above reactions took place above 650℃ in parallel. It was found that hydrogen and carbon for HfC_xH_y were supplied by the reaction of CH_4 with Mg and by thermal decomposition of Mg_2C_3, and carbon of HfC was also supplied by the thermal decomposition of Mg_2C_3. The supply of hydrogen and carbon continued according to a recycle of Mg (Mg→Mg_2C_3→Mg) which exists in the reaction system.
社団法人日本セラミックス協会の論文
1993-03-01