Method and apparatus for the production of precision castings by centrifugal casting with controlled solidification

US6408929B1 · kind B1 · utility

Assignees

• ALD VACUUM TECHNOLOGIES GMBH · DE
• W.C. Heraeus GmbH & Co. KG · DE

Inventors

• Alok Choudhury · Püttlingen, DE
• Harald Scholz · Frankfurt am Main, DE
• Matthias Blum · Büdingen, DE
• Georg Jarczyk · Großkrotzenburg, DE
• Marek Gorywoda · Hanau, DE
• David Francis Lupton · Gelnhausen, DE

Key dates

• Filing date: May 4, 2001
• Grant date: Jun 25, 2002
• Expiry date: May 4, 2021

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B22D27/15
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

In the production of precision castings by centrifugal casting with controlled solidification, a melt is cast under vacuum or shield gas into a pre-heated mold (15) with a central gate (19) and several mold cavities proceeding from the gate toward the outer circumference (Da) of the mold (15). To prevent the formation of shrinkholes and porous areas in the castings, to save energy, and to increase the production rate, the mold (15) is operated at temperatures which decrease from the inside toward the outside. The mold consists of a material or material combination with a coefficient of thermal conductivity lower than that of copper. Before the melt is poured, the mold (15) is heated, starting from the gate (19), by a heating device (20), which projects into the gate, so that the gate (19) reaches a temperature which is a function of the material being cast. Heating is carried out at a rate sufficient to produce a temperature Gradient of at least 100° C., preferably of 200-600° C., even more preferably of 300-500° C., between the inside circumference (Di) and the outside circumference (Da). The invention is used preferable for the production of precision castings of meta…