Elimination of shrinkage cavity in cast ingots

US8347949B2 · kind B2 · utility

Assignee

• Novelis Inc. · US

Inventors

• Mark Douglas Anderson · Basin City, US
• Todd F. Bischoff · Spokane Valley, US
• James E. Boorman · Liberty Lake, US
• Wayne J. Fenton · Spokane, US
• David Sinden · Valleyford, US
• John Steven Tingey · Rathdrum, US
• Robert Bruce Wagstaff · Spokane Valley, US

Key dates

• Filing date: Dec 21, 2011
• Grant date: Jan 8, 2013
• Expiry date: Dec 21, 2031

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B22D19/10
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

An exemplary embodiment provides a method of eliminating a shrinkage cavity in a metal ingot cast by direct chill casting. The method involves casting an upright ingot having an upper surface at an intended height. Upon completion of the casting, the lower tip of the spout is maintained below the molten metal near the center of the upper surface. The metal flow through the spout is terminated and a partial shrinkage cavity is allowed to form as metal of the ingot shrinks and contracts. Before the partial cavity exposes the lower tip of the spout, the cavity is preferably over-filled with molten metal, while avoiding spillage of molten metal, and then the flow of metal through the spout is terminated. These steps are repeated until no further contraction of the metal causes any part of the upper surface to contract below the intended ingot height.