Abstract: Novel metallic systems and methods for their fabrication provide an extreme creep-resistant nano-crystalline metallic material. The material comprises a matrix formed of a solvent metal with crystalline grains having diameters of no more than about 500 nm, and a plurality of dispersed metallic particles formed on the basis of a solute metal in the solvent metal matrix and having diameters of no more than about 200 nm. The particle density along the grain boundary of the matrix is as high as about 2 nm2 of grain boundary area per particle so as to substantially block grain boundary motion and rotation and limit creep at temperatures above 35% of the melting point of the material.

Abstract: Novel metallic systems and methods for their fabrication provide an extreme creep-resistant nano-crystalline metallic material. The material comprises a matrix formed of a solvent metal with crystalline grains having diameters of no more than about 500 nm, and a plurality of dispersed metallic particles formed on the basis of a solute metal in the solvent metal matrix and having diameters of no more than about 200 nm. The particle density along the grain boundary of the matrix is as high as about 2 nm2 of grain boundary area per particle so as to substantially block grain boundary motion and rotation and limit creep at temperatures above 35% of the melting point of the material.

Abstract: A hollow structure, and a method of forming the hollow structure, where the hollow structure includes first and second metal parts, the second metal part having an interior surface and a tapered support member extending from the interior surface. The hollow structure also includes a friction stir welded joint that extends through the first metal part and into the tapered support member.

Abstract: A hollow structure, and a method of forming the hollow structure, where the hollow structure includes first and second metal parts, the second metal part having an interior surface and a tapered support member extending from the interior surface. The hollow structure also includes a friction stir welded joint that extends through the first metal part and into the tapered support member.

Abstract: A hollow structure, and a method of forming the hollow structure, where the hollow structure includes first and second metal parts, the second metal part having an interior surface and a tapered support member extending from the interior surface. The hollow structure also includes a friction stir welded joint that extends through the first metal part and into the tapered support member.

Abstract: A welded structure that includes first and second metal parts derived from Al-RE-TM alloys, which are secured together at a welded joint by friction stir welding.

Abstract: A method for processing a metal part includes extruding an Al-RE-TM alloy to form an extruded part, heating the extruded part, and applying a compressive strain greater than about 50% on the heated part.

Abstract: An internal channel in a metal body for use in applications where internal fluid flow within a metal body is desired, as in a heat exchanger. The internal channel is formed in the metal body by frictionally stirring with a pin plunged into the metal body, and traversing the metal body with the pin.

Abstract: An internal channel in a metal body for use in applications where internal fluid flow within a metal body is desired, as in a heat exchanger. The internal channel is formed in the metal body by frictionally stirring with a pin plunged into the metal body, and traversing the metal body with the pin.

Abstract: An internal channel in a metal body for use in applications where internal fluid flow within a metal body is desired, as in a heat exchanger. The internal channel is formed in the metal body by frictionally stirring with a pin plunged into the metal body, and traversing the metal body with the pin.

Abstract: A shaped metallic component is formed by friction stirring at least a segment of a single piece of bulk metal to impart superplasticity thereto and thereby yield a single superplastic metal blank from the single piece of bulk metal. The metal blank is then deformed by a metal deformation process such as forging, rolling, drawing, bending, extruding, gas forming, punching, and stamping.

Abstract: A method for forming a miniaturized shaped component. Bulk superplastic material is contacted with a flat rotating surface of a rotating tool to frictionally heat the bulk superplastic material with the bulk superplastic material positioned between the flat rotating surface of the tool and a microfabricated tool die. The bulk superplastic material is forced into the microfabricated die once the bulk superplastic material is heated to a temperature between a glass transition temperature and a crystallization temperature.

Abstract: A method for forming a miniaturized shaped component. Bulk superplastic material is contacted with a flat rotating surface of a rotating tool to frictionally heat the bulk superplastic material with the bulk superplastic material positioned between the flat rotating surface of the tool and a microfabricated tool die. The bulk superplastic material is forced into the microfabricated die once the bulk superplastic material is heated to a temperature between a glass transition temperature and a crystallization temperature.

Abstract: A shaped metallic component is formed by friction stirring at least a segment of a single piece of bulk metal to impart superplasticity thereto and thereby yield a single superplastic metal blank from the single piece of bulk metal. The metal blank is then deformed by a metal deformation process such as forging, rolling, drawing, bending, extruding, gas forming, punching, and stamping.

Abstract: Alumina composites of unusually high hardness and toughness are formed by combining alumina and diamond in nanocrystalline form, followed by sintering at high pressure.