Global Patent Index - EP 1043094 A1

EP 1043094 A1 2000-10-11 - Process for making castings

Title (en)

Process for making castings

Title (de)

Verfahren zur Herstellung von Gusswerkstücken

Title (fr)

Procédé de fabrication de pièces coulée

Publication

EP 1043094 A1 (DE)

Application

EP 99107009 A

Priority

EP 99107009 A

Abstract (en)

A quartz-free ceramic investment material, comprising a silica sol of silica content (w) varied for setting expansion ( epsi A) control, is new. A cast article is produced using a casting mould made of a ceramic investment material which comprises a quartz-free oxide ceramic mixture, a binder, a silica sol and an organic carboxylic acid additive and which is expanded, before filling with casti material, for compensation of casting material contraction during cooling. The novelty is that the investment material expansion ( epsilon A), occurring during setting, is controlled by varying the content (w) of colloidal amorphous silicon dioxide in the silica sol. An Independent claim is also included for an investment material for use in the above process.

Abstract (de)

Um ein Verfahren zur Herstellung von Gußwerkstücken insbesondere filigraner Präzisionsgußteile im medizinischen Bereich, bei dem eine aus einer keramischen Einbettmasse bestehende Gießform vor dem Einfüllen eines Gießwerkstoffes zur Kompensation einer beim Abkühlen aus dem schmelzflüssigen Zustand auftretenden Volumenkontraktion des Gießwerkstoffes gezielt expandiert wird, wobei die Einbettmasse aus einer quarzfreien Oxidkeramikmischung (M1, M2) einem Bindemittel und einem als Anmischflüssigkeit dienenden Kieselsol unter Zufügung einer organischen Carbonsäure gebildet wird, zu schaffen, mit dem sich eine vergleichsweise einfache Steuerung der beim Abbinden auftretenden Expansion (A) der quarzfreien Einbettmasse erzielen läßt, wird die beim Abbinden auftretende Expansion (A) der Einbettmasse durch Variieren des Gehalts (w) an kolloidalem, amorphem Siliciumdioxid (SiO2) in dem Kieselsol gesteuert. Ferner wird eine diesbezügliche Einbettmasse angegeben. <IMAGE>

IPC 1-7 (main, further and additional classification)

B22C 1/18

IPC 8 full level (invention and additional information)

B22C 1/00 (2006.01); B22C 1/02 (2006.01); B22C 1/18 (2006.01)

CPC (invention and additional information)

B22C 1/00 (2013.01); B22C 1/02 (2013.01); B22C 1/186 (2013.01)

Citation (search report)

Designated contracting state (EPC)

DE FR GB IT

EPO simple patent family

EP 1043094 A1 20001011; EP 1043094 B1 20081224; DE 59914938 D1 20090205

INPADOC legal status


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2008-06-04 [RTI1] TITLE (CORRECTION)

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