Precision casting and dead-mold casting in plastic/carbon aerogels
AssigneeDLR Deutsches Zentrum für Luft- und Raumfahrt e.V.
InventorsLorenz Ratke, Jochen Fricke
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Abstract
The present invention relates to a molding material for the precision casting and dead-mold casting of metals or metal alloys comprising plastic and/or carbon aerogels, and a process for the preparation of such molding materials. The molding material comprises highly porous open-cell plastic and/or carbon aerogels, obtainable by the sol-gel polymerization of organic plastic materials, optionally followed by partial or complete pyrolysis of the plastic aerogel obtained.
Claims11
A molding material for the precision casting and dead-mold casting of metals or metal alloys comprising highly porous open-cell carbon aerogel, obtained by the sol-gel polymerization of organic plastic materials, followed by partial or complete pyrolysis of the plastic aerogel obtained, said molding material containing inorganic filler materials selected from the group consisting of inorganic fibers and SiC fibers.
A process for the preparation of casting molds for the precision casting and dead-mold casting of metals or metal alloys using highly porous open-cell plastic and/or carbon aerogels, comprising the steps:
- a) wetting a wax mold with a plastic sol of an appropriate composition containing an appropriate catalyst;
- b) converting the sol to a gel at a temperature below the pour point of the wax;
- c) optionally, applying one or more additional layers of the sol each of which is partially or completely convened to the gel form;
- d) drying the gel at a temperature below the pour point of the wax;
- and
- e) melting and draining or burning off the wax from the solidified gel at a temperature above the pour point of the wax.
A process for the preparation of casting molds for the precision casting and dead-mold casting of metals or metal alloys using highly porous open-cell plastic and/or carbon aerogels, comprising the steps:
- a) placing a wax molding in a container;
- b) filling the container partly or wholly with a plastic sol;
- c) converting the sol to the gel form at a temperature below the pour point of the wax;
- d) drying the gel at a temperature below the pour point of the wax;
- and
- e) melting and draining or burning off the wax from the solidified gel at a temperature above the pour point of the wax.
A mold for casting metal articles having a predetermined shape, said mold comprising highly porous open-cell carbon aerogel obtained by sol-gel polymerization of organic plastic material, followed by partial or complete pyrolysis of the plastic aerogel obtained, said carbon aerogel containing inorganic filler materials selected from inorganic fibers or SiC fibers, wherein said open-cell carbon aerogel surrounds a cavity having said predetermined shape.
Dependencies are inferred from the claim text.