Novelis, Inc.

Alcan International Limited

Robert Bruce Wagstaff

Brent Spendlove

Eric W. Reeves

Wayne J. Fenton

Todd F. Bischoff

Kenneth Takeo Kubo

Mark Douglas Anderson

Wayne J Fenton

Todd F Bischoff

Eric W Reeves

Samuel Robert Wagstaff

Milan Felberbaum

Michael R Kosmicki

Tina J Kosmicki

Jeff McDermott

James E Boorman

John Steven Tingey

David Sinden

Randy Womack

Lawrence G Hudson

Jim Boorman

Mark Anderson

Jeff Mcdermott

John Robert Buster Mccallum

James Boorman

Systems and methods are disclosed for using magnetic fields (e.g., changing magnetic fields) to control metal flow conditions during casting (e.g., casting of an ingot, billet, or slab). The magnetic fields can be introduced using rotating permanent magnets or electromagnets. The magnetic fields can be used to induce movement of the molten metal in a desired direction, such as in a rotating pattern around the surface of the molten sump. The magnetic fields can be used to induce metal flow conditions in the molten sump to increase homogeneity in the molten sump and resultant ingot.

Non-contacting molten metal flow control

A method of casting a metal ingot with a microstructure that facilitates further working, such as hot and cold rolling. The metal is cast in a direct chill casting mold, or the equivalent, that directs a spray of coolant liquid onto the outer surface of the ingot to achieve rapid cooling. The coolant is removed from the surface at a location where the emerging embryonic ingot is still not completely solid, such that the latent heat of solidification and the sensible heat of the molten core raises the temperature of the adjacent solid shell to a convergence temperature that is above a transition temperature for in-situ homogenization of the metal. A further conventional homogenization step is then not required. The invention also relates to the heat-treatment of such ingots prior to hot working.

Homogenization and heat-treatment of cast metals

The invention relates to a method and apparatus for direct chill casting ingots with in-situ homogenization. Large particles of eutectic material may form in the solid ingot and the metal may exhibit macrosegregation of alloying components, especially when large ingots are cast in this way. This can be alleviated by applying a first liquid coolant to the ingot emerging from the mold, removing the first liquid coolant at a certain distance along the ingot by means of a wiper, and then applying a second liquid coolant to perform a quench at a greater distance along the ingot. The quench raises the level of the molten sump in the ingot, which helps to overcome the indicated problems, without affecting the desired temperature rebound of the ingot shell (usually at least 425&#xb0; C. (797&#xb0; F.)) for a time effective to cause in-situ homogenization.

In-situ homogenization of DC cast metals with additional quench

A composite metal ingot, comprising at least two layers of differing alloy composition, wherein pairs of adjacent layers consisting of a first alloy and a second alloy are formed by applying the second alloy in a molten state to the surface of the first alloy while the surface of the first alloy is at a temperature between solidus and liquidus temperatures of the first alloy to form an interface there between, wherein the second alloy is a high or medium strength heat treatable aluminum alloy, and further wherein one or more alloy components from the second alloy are present within grain boundaries of the first alloy adjacent said interface.

Composite metal ingot

A composite metal ingot having two or more lengthwise alloy layers including adjacent first and second layers respectively formed of an aluminum-manganese alloy and an aluminum alloy of a different composition wherein the interface between the first and second layers is in the form of a substantially continuous metallurgical bond characterized by the presence of particles of one or more intermetallic compositions containing manganese from the first layer dispersed within a region of the second layer adjacent the interface, the first and second layers having been formed by applying the alloy for the second layer to a self-supporting surface of the first layer while the self-supporting surface is at a temperature between the solidus and liquidus temperatures of the first layer alloy.

Composite metal as cast ingot

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.

Elimination of shrinkage cavity in cast ingots

A method and apparatus is disclosed for casting a composite ingot made of metals that are susceptible to surface oxide formation when molten. The method involves co-casting at least two metal layers from at least two molten metal pools formed within a direct chill casting apparatus. During the casting operation, movement of metal oxide formed on the upper surface of at least one of the pools towards an edge of the pool is restrained by an oxide skimmer positioned close to an edge of the pool above an external surface or metal-metal interface of the ingot. The apparatus provides a DC caster with at least one oxide skimmer that operates in this manner.

Oxide restraint during co-casting of metals

An apparatus is described for the casting of a composite metal ingot having two or more separately formed layers of one or more alloys. An open ended annular mould is provided having a divider wall dividing a feed end of the mould into at least two separate feed chambers. For each pair of adjacent feed chambers, a first alloy stream is fed through one of the pair of feed chambers into the mould and a second alloy stream is fed through another of the feed chambers. A self-supporting surface is generated on the surface of the first alloy stream and the second alloy stream is contacted with the first stream. By carefully selecting conditions and positions where the alloy streams meet, a composite metal ingot is formed in which the alloy layers are mutually attached with a substantially continuous metallurgical bond.

Method for casting composite ingot

A method and apparatus are disclosed for sequentially direct chill casting a composite ingot made of metals having similar freezing ranges. Poor adhesion between the layers and low reliability of casting are addressed by adjusting the position of secondary cooling (created by applying water streams to the emerging ingot) relative to the upper surfaces of the molten metal pools compared to the conventional positions of first application of the secondary cooling. This can be achieved by moving one or more walls of the mold (when the secondary cooling emanates from the bottom of such walls), or adjusting the height of the molten metal pools within the mold and moving cooled divider walls between the pools. The relative temperatures and conditions of the metals at positions where they meet at the metal interface may therefore be optimized.

Sequential casting of metals having similar freezing ranges

A method and apparatus are described for the casting of a composite metal ingot having two or more separately formed layers of one or more alloys. An open ended annular mould is provided having a divider wall dividing a feed end of the mould into at least two separate feed chambers. For each pair of adjacent feed chambers, a first alloy stream is fed through one of the pair of feed chambers into the mould and a second alloy stream is fed through another of the feed chambers. A self-supporting surface is generated on the surface of the first alloy stream and the second alloy stream is contacted with the first stream. By carefully selecting conditions and positions where the alloy streams meet, a composite metal ingot is formed in which the alloy layers are mutually attached with a substantially continuous metallurgical bond.

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Spokane, WA, United States of America

Wayne J Fenton