Method for producing composite material having an aluminum alloy matrix with a silicon carbide reinforcement

The method for producing a composite material having a matrix of aluminum-magnesium alloy and at least about 7% up to about 20%, by volume of a discontinuous phase from the group consisting of silicon carbide particles and silicon carbide fibers, and up to about 5%, by volume, of titanium carbide particles which comprises preparing a bath of aluminum alloy containing about 4% to about 7% magnesium, mixing said discontinuous phase material with said bath at a temperature above the liquidus temperature thereof for a time sufficient to provide substantially complete dispersion of said material throughout said bath and solidifying said bath while maintaining said dispersion to provide a solid composite having silicon carbide reinforcement throughout an aluminum alloy matrix, and thereafter hot working said composite at a temperature between the liquidus and solidus temperatures of said aluminum alloy matrix, said matrix being 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.