The present invention relates to a novel method for forming metal matrix composite bodies and novel products produced by the method. Particularly, a permeable mass of filler material or a preform is provided which has included therein at least two different matrix metal powders. Moreover, an infiltration enhancer and/or an infiltration enhancer precursor and/or an infiltrating atmosphere are in communication with the filler material or preform, at least at some point during the process, which permits molten matrix metal, upon contact with the filler material or preform, to spontaneously infiltrate the filler material or preform. The presence of powdered matrix metal in the preform or filler material reduces the relative volume fraction of filler material to matrix metal.