Abstract: The invention provides a method for heat treating aluminum-base alloys. The method increases stress corrosion resistance after heating of the alloy to temperatures between 100.degree. C. and 150.degree. C. A dispersion strengthened aluminum-base alloy containing lithium and magnesium is shaped to form an object of substantially final form. The dispersion strengthened aluminum-base alloy is heated to a temperature between 160.degree. C. and 250.degree. C. for at least 3 hours. The heat treated object has increased stress corrosion resistance after exposure to temperatures between 100.degree. C. and 150.degree. C.

Abstract: A process for decreasing the embrittling tendency of lithium in aluminum-base alloy compositions containing lithium comprising incorporating silicon in the alloy composition and forming the alloy as a dispersion strengthened powder, and dispersion strengthened aluminum-base alloy compositions comprised of aluminum, lithium and silicon having improved properties.

Abstract: A process for producing composite materials which comprises subjecting particles of a malleable matrix material, i.e., a metal or alloy or the components of a matrix alloy and particles of a reinforcing material such as a carbide or an oxide or an intermetallic to energetic mechanical milling under circumstances to insure the pulverulent nature of the mill charge so as to enfold matrix material around each of said reinforcing particles to provide a bond between the matrix material and the surface of the reinforcing particle. The process is exemplified by the use of aluminum alloy as the matrix material and silicon carbide as the reinforcing particles. Reinforcing particles are present in an amount of about 0.2 to about 30 volume percent of total matrix and reinforcing particles. The invention is also directed to the product of the process.

Abstract: A process for producing composite materials which comprises subjecting particles of a malleable matrix material, i.e., a metal or alloy or the components of a matrix alloy and particles of a reinforcing material such as a carbide or an oxide or an intermetallic to energetic mechanical milling under circumstances to insure the pulverulent nature of the mill charge so as to enfold matrix material around each of said reinforcing particles to provide a bond between the matrix material and the surface of the reinforcing particle. The process is exemplified by the use of aluminum alloy as the matrix material and silicon carbide as the reinforcing particles. Reinforcing particles are present in an amount of about 0.2 to about 30 volume percent of total matrix and reinforcing particles. The invention is also directed to the product of the process.

Abstract: Master alloys of lithium or other alkali metal with a second metal such as alumium are made by exposing mechanically aloyed powder of the second metal to molten alkali metal. The exposure can be in an inert liquid medium such as a high boiling point hydrocarbon or in a dry, inert gas medium. In order that contact between the lithium and the second metal be efficient, significant, shear inducing agitation is required when the process is carried out in a liquid medium and kneading action, either manual or mechanical is required when the process is carried out dry in an inert gas medium.

Abstract: An improved process for hot working of dispersion-strengthened mechanically alloyed aluminum is provided based on a disclosed unconventional response of such material to thermomechanical processing. The process permits optimization of strength and workability and the production of aluminum alloys of very high strength.

Abstract: An improved dispersion strengthened aluminum-base alloy and an improved method for producing the alloy are provided. A preferred alloy comprises, by weight, about 3 to 5% Mg, about 0.2-2.5% C, and about 0.3 to 4% O and the balance essentially aluminum.