Composite material including alumina-silica short fiber reinforcing

Abstract

A composite material is made from alumina-silica type short fibers embedded in a matrix of metal. The matrix metal is an alloy consisting essentially of from approximately 2% to approximately 6% of copper, from approximately 0.5% to approximately 3.5% of magnesium, and remainder substantially aluminum. The short fibers have a composition of from about 35% to about 80% of Al.sub.2 O.sub.3 and from about 65% to about 20% of SiO.sub.2 with less than about 10% of other included constituents, and may be either amorphous or crystalline, in the latter case optionally containing a proportion of the mullite crystalline form. The fiber volume proportion of the alumina-silica type short fibers is between approximately 5% and approximately 50%, and may more desirably be between approximately 5% and approximately 40%. If the alumina-silica short fibers are formed from amorphous alumina-silica material, the magnesium content of the aluminum alloy matrix metal may desirably be between approximately 0.5% and approximately 3%. And, in the desirable case that the fiber volume proportion of the alumina-silica type short fibers is between approximately 30% and approximately 40%, then the copper content of the aluminum alloy matrix metal is desired to be between approximately 2% and approximately 5.5%.