Multi-Layered Stuctures

摘要

1,190,437. Laminates. NORTH AMERICAN ROCKWELL CORP. 10 July, 1967 [22 July, 1966], No. 31711/67. Addition to 1,156,041. Heading B5N. [Also in Division C1] In a coherent multilayered structure, each layer consists of pyrolysed para-polyphenylene, or a carbide resulting from the reaction of a material with para-polyphenylene on pyrolisis thereof, or a pyrolysed mixture of para-polyphenylene with an inert filler, and one layer at least is of a different composition from the other layer or layers. The structure may be formed by forming a plurality of successive layers of para-polyphenylene powder, one or more of the layers containing an inert filler, or a material which will carbonize in situ on pyrolysis of the para-polyphenylene and being of a different composition from the other layer or layers, compacting the layers to form a coherent multilayered body, and heating the compacted body to a temperature at least sufficient to pyrolyse the para-polyphenylene. The powder layers may be inserted in turn into a die and all compacted at once or the layer(s) may be compacted within the die after the insertion of each layer, or each layer may be compacted in a separate die and roughened before assembling the layers and compacting them together. The inert filler may be graphite powder, boron, a metalloid, a metal, a carbide, or a silicide. The reactive material may be silicon, titanium, zirconium or molybdenum which may be present in a stoichiometric amount required to form the carbide thereof at the pyrolysis temperature. In one example the structure comprises an oxidation resistant layer of silicon carbide and a heat conductive layer comprising graphite and pyrolysed para-polyphenylene. In one example, the layers form the core and annular shell of a cylinder.