| abstract |
In one embodiment, in a composition (10) mixed with a molten metal that forms a metal matrix composite, the composition does not wet the molten aluminum and / or is not chemically stable in the molten aluminum. Filler (12) characterized by a ceramic reinforcing filler (12) wetted with molten aluminum and coated with a ceramic material that is chemically stable in molten aluminum. In a related aspect, in a composition (20) for making a porous preform impregnated with molten metal to form a metal matrix composite, the composition is a ceramic reinforcing filler that is not wetted by molten aluminum, the ceramic being wetted by molten aluminum Characterized by a ceramic reinforcing filler (23) that is coated with a material (22) and optionally with a metal such as nickel. The ceramic material can be coated on the ceramic reinforcing filler by a vacuum deposition technique such as vacuum sputtering. |