Method for forming metal matrix composites having variable filler loadings and products produced thereby

A method for forming a metal matrix composite body comprising:

• mixing together at least two powdered matrix metals with at least one material selected from the group consisting of a filler material and a preform to form a permeable mass;
• contacting said permeable mass with a source of molten matrix metal alloy in the presence of an infiltrating atmosphere;
• providing at least one of an infiltration enhancer and an infiltration enhancer precursor to at least one of said permeable mass and said infiltrating atmosphere to cause spontaneous infiltration of the matrix metal into the permeable mass to occur;
• spontaneously infiltrating at least a portion of the permeable mass with molten matrix metal, said filler material and said preform being substantially non-reactive with the powdered matrix metals and the molten matrix metal;
• and
• cooling said matrix metal within said permeable mass thereby forming a metal matrix composite body.