Patent EP-1876158-A1 (EP)
Inventor: SCHMIDT JENS
IPC: C04B35/52
Filed: 2007-06-25
Abstract: The manufacturing of carbide ceramic components useful as friction body or heat sink, comprises manufacturing a composite of prefabricated units (10) from a cellulose-containing powder using injection molding or pressing process, holding the prefabricated units at adjacent prefabricated unit by a junction element, and pyrolyzing and/or graphitizing the composite of prefabricated units. The composite is porous and comprises prefabricated bodies (16) for the component. A carbide former infiltration process is carried out by using a metal melt at the pyrolyzed composite in pressure-free manner. The manufacturing of carbide ceramic components useful as friction body or heat sink, comprises manufacturing a composite of prefabricated units (10) from a cellulose-containing powder using injection molding or pressing process, holding the prefabricated units at an adjacent prefabricated unit by a junction element, and pyrolyzing and/or graphitizing the composite of prefabricated units. The composite is porous and comprises prefabricated bodies (16) for the component. A carbide former infiltration process is carried out by using a metal melt at the pyrolyzed composite in a pressure-free manner. The junction element has a width of 0.5-10 mm and a height of 0.5-10 mm that is smaller than the height of the prefabricated unit. The composite of prefabricated units is manufactured. A mould form, which is provided with a structure that is asymmetrically opposite to that of the junction element, is used. The asymmetrically opposite structure of the junction element has recesses and is arranged below a bottom die or is inserted into an impression die. A starting material is added to the composite of the prefabricated unit. An upper die is segmented in a manner adapted to the asymmetrically opposite structure of the junction element. After a compression molding process, the opposite structure of the junction element is removed from the press die before the removal of the composite of prefabricated units. The junction elements are provided with an extra reinforcing material structure for the purpose of stabilization. The reinforcing material structure is a woven, knitted or non-woven fabric. Predetermined breaking points are produced during the molding process of the junction element by the choice of materials. The junction element is produced in such a manner that it is more brittle than a carbide ceramic component. The junction element is produced with a higher carbide ceramic proportion than the carbide ceramic component. The composite of the prefabricated units is evenly loaded during the pyrolysis process and is superimposed one above the other for the pyrolysis process. The junction elements are produced at or near an upper or lower surface of the prefabricated units. The junction elements or the junction element attachments are removed at the carbide ceramic components. A composite of carbide ceramic components is held at a support device for the removal of the junction elements or the junction element attachments by a mechanical and/or laser machining. An abrasive grinding process takes place on the ceramic components. The carbide forming fibers are incorporated during the manufacture of the composite of prefabricated units at the junction elements and/or between the prefabricated units. Independent claims are included for: (1) composite of prefabricated units for manufacturing carbide ceramic components; and (2) carbide ceramic components.