Patent ID: 7793703

Claim:
A method of forming a metal matrix composite by infiltrating a preform with a metal with the preform having an inner surface and an opposing outer surface and formed from a composition having ceramic particles and ceramic fibers with the ceramic fibers having an aspect ratio of greater than 3:1 utilizing a multi-screw extruder having at least three intermeshing screws and a mold having a cavity, said method comprising the steps of: extruding the composition through the multi-screw extruder to form an extrudate; substantially randomly orienting the ceramic fibers in three dimensions as the composition is extruded through the multi-screw extruder; forming the extrudate to a desired configuration for defining the preform; heating the preform for strengthening the preform; positioning the preform within a portion of the cavity of the mold; heating the metal above a melting point of the metal for forming a molten metal; injecting the molten metal into the cavity of the mold adjacent the outer surface of the perform under pressure; infiltrating the preform with the molten metal through the outer surface of the preform to the inner surface of the preform; cooling the molten metal to below the melting point to solidify the molten metal and define the metal matrix composite having a wear surface formed of the infiltrated inner surface of the preform with exposed metal, ceramic particles and ceramic fibers; and removing the metal matrix composite from the mold.