Process for pressure infiltration casting and fusion bonding of a metal matrix composite component in a metallic article

A process for pressure infiltration casting of a metal matrix composite in a metallic article, comprising the steps of:

• selecting a base metal for forming a metallic base component, said base metal having a melting temperature;
• forming said metallic base component having a shape of preslected dimensions and an exterior surface of a preselected configuration, at least a portion of said exterior surface of said metallic base component being adapted for mating with a corresponding exterior surface of a preform;
• selecting a material for forming said preform, said material being selected from one of ceramics, cermets, or mixtures thereof;
• forming said preform having an exterior surface of a preselected configuration, at least a portion of said exterior surface of said preform being adapted for mating with said corresponding exterior surface of said metallic base, and said preform having interconnecting porosity;
• selecting an infiltration metal for forming a molten infiltrant charge, said infiltration metal having a melting temperature at least equal to or greater than the melting temperature of said base metal;
• providing a first mold having a first mold cavity including said metallic base component;
• preheating said first mold and said metallic base component to a temperature in the range of about (x-200).degree.F. to about (x-50).degree.F., wherein x is said melting temperature of said base metal;
• providing a second mold having a second mold cavity including said preform and said infiltration metal;
• positioning said second mold adjacent said first mold and mating a portion of said exterior surface of said preform with a corresponding exterior surface of said metallic base and forming an interface;
• heating said second mold, said preform and said infiltration metal to a temperature in the range of about (y-200).degree.F. to about (y+200).degree.F., wherein y is said melting temperature of said infiltration metal, and forming a preheated preform and said molten infiltrant charge;
• evacuating said preform and isolating a vacuum in said preform;
• pressurizing said molten infiltrant charge at a pressure sufficient for infiltrating said molten charge into said interconnecting porosity of said preform and forming an infiltrated preform;
• contacting said molten infiltration charge with said preheated base metal at said interface;
• melting at portion of said base metal at said interface, fusion-bonding said infiltration metal with said base metal at said interface, and forming a fusion bond interface;
• and
• cooling said metallic base and causing directional solidification of said infiltration metal from said fusion bond interface to said exterior surface of said preform.