Dural Aluminum Composites Corp.

Alcan International Limited

Alcan Aluminum Corporation

Mc21 Incorporated

Metallic Composites for the 21st Century, Inc.

Michael D Skibo

David M Schuster

Richard S Bruski

Larry G Hudson

Iljoon Jin

David James Lloyd

Donald E Hammond

Inge L Hansson

A metal matrix composite (MMC) material machining tool and a method for forming such a tool. In one embodiment, the MMC machining tool of the present invention is comprised of a support disk. In this embodiment, the MMC machining tool is further comprised of a plating material which is bonded to at least a portion of the support disk. The present embodiment further recites a plurality of diamond particles coupled to the plating material such that the plurality of diamond particles are securely plated to at least a portion of the support disk. In this embodiment, the plurality of diamond particles are securely plated to the support disk in a manner such that the plurality of diamond particles are adapted to machine metal matrix composite material.

High-speed, low-cost, machining of metal matrix composites

A method for mixing particles in a liquid or semi-liquid medium, such as ceramic reinforcing particles in a molten metal or metal alloy matrix for the production of stir-cast metal matrix composite (MMC) materials. The particles can be introduced under the surface of the matrix by feeding the particles through the inner passage of a rotatable hollow impeller tube. The impeller tube is terminated at its lower end by an impeller head that includes teeth positioned proximate to an impeller base. The particles enter the matrix through a shear region in and around the volume between the impeller base and the impeller head. The rotating impeller and the high shear force thereby created wet the particles in the composite matrix and effect homogenization of the composite matrix. The present invention may be practiced either under vacuum or atmospheric pressure.

Method for mixing particles into a liquid medium

An apparatus for mixing particles in a liquid or semi-liquid medium, such as ceramic reinforcing particles in a molten metal or metal alloy matrix for the production of stir-cast metal matrix composite (MMC) materials. The particles can be introduced under the surface of the matrix by feeding the particles through the inner passage of a rotatable hollow impeller tube. The impeller tube is terminated at its lower end by an impeller head that includes teeth positioned proximate to an impeller base. The particles enter the matrix through a shear region in and around the volume between the impeller base and the impeller head. The rotating impeller and the high shear force thereby created wet the particles in the composite matrix and effect homogenization of the composite matrix. The present invention may be practiced either under vacuum or atmospheric pressure.

Apparatus for mixing particles into a liquid medium

A method and apparatus are provided for mixing nonmetallic reinforcing particles into a molten metal or metal alloy for the production of stir-cast metal matrix composite (MMC) materials under atmospheric or near-atmospheric pressure. In a preferred embodiment, the particles are introduced into the matrix under the surface of the matrix by feeding the particles through the inner passage of a rotatable hollow impeller tube positioned in the matrix. The impeller tube is terminated at its lower end by an impeller head. The impeller head includes one or more teeth and is positioned proximate to an impeller base. The particles enter the matrix through a shear region which exists in and around the volume between the impeller base and the impeller head. The rotating impeller and the high shear force thereby created wet the particles in the composite matrix and effect homogenization of the composite matrix. The particles are preferably fed into the matrix from a particle supply that is back-filled with an active gas like oxygen or a substantially inert gas. The process of the present invention may be practiced as a batch process or as a continuous process.

Preparation of metal matrix composites under atmospheric pressure

A composite material mixture of free flowing reinforcement particles in a molten metal is solidified at a cooling rate greater than about 15.degree. C. per second between the liquidus and solidus temperatures of the matrix alloy. This high cooling rate imparts a homogeneous structure to the solid composite material. Care is taken to avoid the introduction of gas bubbles into the molten composite material while the mixture is stirred to prevent segregation of the particles. For viscous melts, an artificial surface layer such as a fiberglass blanket may be used to prevent entrapment of bubbles during pre-casting stirring. Additionally, gas bubbles are removed from the molten mixture by filtering and skimming.

Apparatus and process for casting metal matrix composite materials

A method and apparatus for preparing a continuous flow of castable composite materials of nonmetallic particles in a metallic matrix, wherein particles are mixed into a molten metallic alloy to wet the molten metal to the particles, and the particles and metal are sheared past each other to promote wetting of the particles by the metal. The mixing occurs while minimizing the introduction of gas into the mixture, and while minimizing the retention of gas at the particle-liquid interface. Mixing is done at or below a maximum temperature whereat the particles do not substantially chemically degrade in the molten metal during the time required for processing, and casting is done at a temperature sufficiently high that there is no solid metal present in the melt.

Apparatus for continuously preparing castable metal matrix composite

A cast composite material is made from particles and a matrix alloy of preselected composition that is difficult to wet to the particles. A wetting alloy having a composition that readily wets the particles is first mixed with the particles under conditions that wet the wetting alloy to the particles. The wetting alloy is selected so that it has no alloying elements in excess of that in the preselected matrix alloy, and preferably with wettability inhibiting elements reduced. After wetting and mixing have been achieved, the remaining alloying ingredients are added to the melt to adjust the matrix to the desired composition. The approach is applicable to cast composite materials containing both reactive and nonreactive particles.

Stepped alloying in the production of cast composite materials

A cast composite material is formed from about 5 to about 35 volume percent of particulate reinforcement, preferably silicon carbide particles, embedded in an aluminum alloy matrix having from about 8.5 to about 12.6, most preferably about 9.5 to about 11.0, weight percent silicon. The cast composite material is particularly well suited for use as a foundry alloy for remelting purposes. Other alloying elements may be added without interfering with the beneficial effects of the silicon.

Cast composite material with high-silicon aluminum matrix alloy and its

A method for preparing a composite material comprises the steps of providing a first mixture of a molten aluminum-base matrix alloy having at least about 4 percent by weight magnesium, and a mass of discontinuous reinforcing particles that are not soluble in the molten matrix alloy, and mixing the first mixture to wet the matrix alloy to the particles and to distribute the particles throughout the volume of the molten matrix alloy. The first matrix alloy is diluted to reduce the magnesium content of the mixture to less than about 4 percent by weight magnesium, to produce a second mixture, and the second mixture is cast. The second mixture has at least about 5 volume percent particles, and preferably has about 5-25 volume percent particles.

Cast composite materials having an Al-Mg matrix alloy

Cast compsoite material with high silicon aluminum matrix alloy and its

A method and apparatus for preparing cast composite materials of nonmetallic particles in a metallic matrix, wherein particles are mixed into a molten metallic alloy to wet the molten metal to the particles, and the particles and metal are sheared past each other to promote wetting of the particles by the metal. The mixing occurs while minimizing the introduction of gas into the mixture, and while minimizing the retention of gas at the particle-liquid interface. Mixing is done at a maximum temperature whereat the particles do not substantially chemically degrade in the molten metal during the time required for processing, and casting is done at a temperature sufficiently high that there is no solid metal present in the melt. Mixing is preferably accomplished with a dispersing impeller, or a dispersing impeller used with a sweeping impeller.

Cast composite material

A cast composite material is made from particles and a matrix alloy of preselected composition that is difficult to wet to the particles. A wetting alloy having a composition that readily wets the particles is first mixed with the particles under conditions that wet the wetting alloy to the particles. The wetting alloy is selected so that is has no alloying elements in excess of that in the preselected matrix alloy, and preferably with wettability inhibiting elements reduced. After wetting and mixing have been achieved, the remaining alloying ingredients are added to the melt to adjust the matrix to the desired composition. The approach is applicable to cast composite materials containing both reactive and nonreactive particles. (aluminum matrix with silicon additions).

Stepped alloying in the production of cast composite materials (aluminum

A cast composite material is prepared from a modified aluminum-containing matrix and reinforcement particles mixed into the matrix. From about 15 to about 130, preferably from about 20 to about 50, parts per million of an element, preferably beryllium, that forms a more stable oxide than magnesium oxide is included in the matrix alloy. The stable-oxide-forming element reduces the amount and thickness of the aluminum oxide and other oxides formed at the surface of the melt, which otherwise may be mixed into the melt to cause microstructural irregularities in the matrix of the cast composite material.

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Leucadia, CA, United States of America

Michael D Skibo