| 摘要 |
1,264,720. Silicon carbide whiskers. LONZA Ltd. 29 June, 1970 [4 Aug., 1969], No. 31305/70. Heading C1A. SiC whiskers are grown on a substrate to whose surface has been applied a surface coating of an oxygen containing iron compound, from a gas phase containing Si, C and H, at 1000- 1600‹ C. The substrate may be carbon, graphite, mullite, Al 2 O 3 or SiC. The iron compound may be a simple or complex salt of an organic acid or of an oxygen containing inorganic acid, or iron carbonyl. The salt may be added as a solution or suspension, and the solution may be in alcohol or water and in the latter case a wetting agent may be added, the substrate being immersed for 0À5-5À0 minutes to achieve the surface coating. The silicon may be present as the element or as a mixture of silicon dioxide and carbon. The carbon may be present as a gaseous hydrocarbon. The reaction pressure is preferably 0À5-2 ats. and the gaseous byproducts are removed by allowing hydrogen to flow through the reaction vessel, a flow rate of 0À1-5 1./hr. being preferred. |
