Patent GB-801383-A (GB)
Title: Improvements in and relating to refractory materials
Inventor: MOORE NORMAN CLEMENT
IPC: C04B35/58
Filed: 1953-11-25
Abstract: A composite body of molybdenum disilicide and alumina is made by preparing a fluid suspension of molybdenum disilicide, making therefrom a coherent, relatively thin and self-supporting element consisting principally of molybdenum disilicide, and applying it to a coherent mass of alumina.  In an example, molybdenum disilicide is prepared by the exothermic reaction of molybdenum and silicon powders in a water-jacketed cylinder, and is ball-milled to small particle size and mixed with any further materials, e.g. copper, which may be required to modify the finished coating.  The powder is then suspended in a solution of cellulose aceto-butyrate in ethylene dichloride, and the suspension is deaerated, coated on a suitable base, such as a glass plate, and dried to give a flexible film, which can be cut or stamped to shape.  A cylinder is prepared by compacting alumina powder by pressure, and is surrounded by a <PICT:0801383/III/1> piece of the film, placed in a graphite mould, and sintered under pressure.  Bodies of other shapes may be coated and localized conductive areas can be applied, e.g. to form printed circuits. An apparatus for producing the film comprises a base 30 on which a glass plate 34 is supported.  A hopper 35 with an adjustable gate 36 and containing a quantity of the molybdenum disulphide suspension, is drawn over the plate 34 by a rod 41, a cable 44 and a winch 45 driven by a small motor, not shown.  Specification 779,128, [Group II], is referred to.ALSO:A composite body of molybdenum disilicide and alumina is made by preparing a fluid suspension of molybdenum disilicide, making therefrom a coherent, relatively thin and self-supporting element consisting principally of molybdenum disilicide, and applying it to a coherent mass of alumina.  In an example, molybdenum disilicide is prepared by the exothermic reaction of molybdenum and silicon powders in a water jacketed cylinder, and is ball-milled to small particle size and mixed with any further materials, e.g. copper, which may be required to modify the finished coating.  The powder is then suspended in a solution of cellulose aceto-butyrate in ethylene dichloride, and the suspension is de-aerated, coated on a suitable base, such as a glass plate, and dried to give a flexible film, which can be cut or stamped to shape. A cylinder is prepared by compacting alumina powder by pressure, and is surrounded by a piece of the film, placed in a graphite mould, and sintered under pressure.  Bodies of other shapes may be coated and localized conductive areas can be applied, e.g. to form printed circuits.  Specification 779,128 is referred to.ALSO:A composite body of molybdenum disilicide and alumina is made by preparing a fluid suspension of molybdenum disilicide, making therefrom a coherent, relatively thin and self-supporting element consisting principally of molybdenum disilicide, and applying it to a coherent mass of alumina. In an example, molybdenum disilicide is prepared by the exothermic reaction of molybdenum and silicon powders in a water jacketed cylinder, and is ball-milled to small particle size and mixed with any further materials, e.g. copper, which may be required to modify the finished coating.  The powder is then suspended in a solution of cellulose aceto-buytrate in ethylene dichloride, and the suspension is de-aerated, coated on a suitable base, such as a glass plate, and dried to give a flexible film, which can be cut or stamped to shape. A cylinder is prepared by compacting alumina powder by pressure, and is surrounded by a piece of the film, placed in a graphite mould, and sintered under pressure.  Bodies of other shapes may be coated and localised conductive areas can be applied e.g. to form printed circuits.  Specification 779,128 is referred to.