Abstract: A method for wetting and bonding refractory alumina or aluminosilicate fibers or particles with molten aluminum or aluminum alloys by forming a boron oxidized interface between the fiber and the metal is exists. The method comprises the steps of (a) coating alumina fibers with an effective amount of a thermally decomposable precursor of boron oxide; (b) heating the coated fiber sufficiently to form a boron oxide; and (c) forming a composite with aluminum metal or an aluminum alloy. Thermally decomposable precursors of boron oxide include ammonium pentaborate, ammonium diborate and orthoboric acid.

Abstract: An aluminum alloy matrix composite containing alumina or aluminum silicate reinforcement whereby said composite material exhibits wetting between said reinforcement and said aluminum alloy. The composite comprises (a) alumina or aluminosilicate reinforcement; (b) a matrix of aluminum or aluminum alloy; and (c) an intelayer of mixed oxides of aluminum and boron wherein the interlayer of mixed oxides of aluminum and boron includes but is not limited to the following oxides, B.sub.2 O.sub.3, Al.sub.2 O.sub.3, 2Al.sub.2 O.sub.3.B.sub.2 O.sub.3 and 9Al.sub.2 O.sub.3 2B.sub.2 O.sub.3 at the interface between said reinforcement and said matrix.