| 摘要 |
1,236,913. Silicon carbide whiskers. NATIONAL RESEARCH DEVELOPMENT CORP. 1 July, 1968 [29 March, 1967], No. 14211/67. Heading C1A. Silicon carbide whiskers are made by reacting SiO vapour and CO in the presence of H 2 and solid phase carbon at a temperature between 1200‹ and 1600‹ C., adjacent to a substrate which is heated to a temperature greater than 1200‹ C., upon which SiC whiskers are formed. Preferably the reactants are present in the molar ratios SiO: CO of 1:1 and H 2 : CO of at least 2:1. SiO vapour may be generated by heating a substantially equimolar mixture of Si and SiO 2 to a temperature of at least 1200‹ C. and the evolved vapour may then be flushed into contact with the other reactants by a stream of inert gas. The reaction is preferably carried out at a reduced pressure of about 10 Torr. The specified substrates are SiC, Si 3 N 4 , Al 2 O 3 , mullite and carbon. |
