Abstract: A method is provided for producing a wrought aluminum eutectic composite characterized by improved physical properties. The method resides in forming a casting of an aluminum alloy characterized metallographically by the presence of a eutectic structure, and then heat treating the casting at a temperature related to the eutectic-forming temperature of said alloy casting, that is just below its incipient melting point. The heat treatment is continued for a time at least sufficient to convert the morphology of the eutectic to dispersed fine particles of reinforcing phase(s), following which the alloy is physically worked to reduce the cross section thereof and provide a wrought aluminum eutectic composite characterized by improved physical properties.

Abstract: Reinforced composite aluminum-matrix articles containing up to 20%, by volume, silicon carbide fibers or particles, are produced by a casting process wherein about 4% to about 7%, by weight, of magnesium is included in the aluminum matrix alloy to facilitate wetting of the reinforcing material and ready dispersal thereof with the matrix alloy while the alloy is completely molten and thereafter hot working the composite at a temperature between the liquidus and solidus temperatures of the aluminum alloy matrix. The matrix is characterized by a microstructure wherein fine precipitates appear in the vicinity of SiC particles or fibers, and by high hardness and strength without further heat treatment.

Abstract: Reinforced composite aluminum-matrix articles containing a non-oxide reinforcing material, such as silicon carbide fibers or particles, are produced by a casting process wherein a small amount of lithium less than about 1%, by weight, is included in a melt of aluminum matrix alloy to facilitate wetting of the reinforcing material and ready dispersal thereof in the aluminum matrix alloy.