| 摘要 |
1378477 Mullite INTERNATIONAL BUSINESS MACHINES CORP 29 March 1973 [20 June 1972] 15107/73 Heading C1A Mullite is made by forming a first mixture of compounds of aluminium and silicon and adjusting the relative proportions of Al and Si from that theoretically required to form mullite (3Al 2 O 3 .2SiO 2 ), to compensate for the alumina and/or silica that is added in a future grinding process, heating said first mixture to partially react the components to form a second mixture comprising Al 2 O 3 , SiO 2 and 3Al 2 O 3 2SiO 2 comminuting said mixture, during which step the relative proportions of Al and Si are changed by the inherent addition of alumina and/or silica from an alumina and/or silica grinding mill, to those required to form mullite, followed by mixing with a binder and solvent and heating to form the mullite. The first mixture may be heated to 1300‹ to 1400‹C. The milled second mixture may be combined with binder and solvent to form a dispersion. A suitable binder may be formed by combining a polyvinylbutyral resin or polymer with a plasticizer such as dioctylphthalate or dibutylphthalate; other suitable polymers are polyvinylformal, polyvinylchloride and polyvinyl acetate. The dispersion may cast into a sheet, dried and sintered at 1500-1600‹ C. to form the mullite. |
