Aluminum metal matrix composite materials reinforced by intermetallic compounds and alumina whiskers

Abstract

A process for making composite materials, namely reinforced Al-metal matrix composites based on either: (I) Al—W intermetallic phase and Al2O3 ceramic whiskers, or (II) Al—Mo intermetallic phase and Al2O3 ceramic whiskers. This process involves the oxidation of aluminum using tungsten oxide in powder form for product I, and that of aluminum and molybdenum oxide in powder form for product II. Product I contains an Al—W intermetallic phase, some sapphire whiskers, and a continuous Al-metal matrix. Product II contains an Al—Mo intermetallic phase, sapphire whiskers, and a continuous Al-metal matrix. The alumina whiskers are formed as a result of two reactions. They are: (i) the oxidation between the pre-mixed Al and the oxide, and (ii) the oxidation of Al with the atmospheric environment in the presence of the oxide, which acts as a catalytic agent for the reaction. These newly invented products are hard, strong and light. They are fabricated at above the melting point of aluminum, typically above 800° C. and preferably around 1000° C., and no sophisticated facility is required in the production process. Based on the above powder mixtures of I, or II, additional powders, for example. carbon (C), silicon dioxide (SO2) or other metal oxides, can be mixed to further improve the structural properties of the composites.

Dependencies are inferred from the claim text.