Infiltrated powered metal composite article

A precision molded die cavity comprising:

• (a) less than about 15 volume percent granules of tungsten of about 1 to about 44 micrometers mean diameter;
• (b) about 35 to about 70 volume percent of a monolithic ferroalloy skeleton, said ferroalloy fully enveloping the majority of said tungsten granules, all of the latter being uniformly dispersed in said skeleton;
• and
• (c) about 15 to about 50 volume percent of a continuous metallic phase comprising copper, said continuous metallic phase occupying the connected porosity in said skeleton:
• said article thereby comprising two intermeshed matrices and being substantially free of voids.

A process for forming a precision molded composite article, comprising the steps of:

• (a) blending granules of a first metal or alloy having about 1 to about 100 micrometers mean diameter with granules of a second metal or alloy having about 1 to about 100 micrometers mean diameter, said second metal or alloy having a higher Rockwell hardness than said first metal or alloy, thereby forming a uniform mixture;
• (b) mixing said uniform mixture with up to 50 volume percent of a heat fugitive, organic binder;
• (c) molding the resulting mixture in a heated flexible mold, cooling said mold and its contents to room temperature, and demolding said contents by applying a vacuum to the outside of said mold thereby forming an essentially void-free green molded preform having the size and shape of said mold;
• (d) heating said green molded preform to thermally remove said binder and form a rigid, handleable skeletal preform;
• (e) placing said skeletal preform in contact with a third metal or alloy which will wet said skeleton and which has a Rockwell hardness less than or equal to the Rockwell hardness of said second metal or alloy;
• (f) infiltrating said skeletal preform with said third metal or alloy by heating said skeletal preform and said third metal or alloy above the melting point of said third metal, but below the melting point of said second metal or alloy, whereby said third metal or alloy melts and wicks into the connected porosity of said prerorm by capillary action and said second metal or alloy fully envelopes the majority of said granules of first metal or alloy, with the proviso that said granules of first metal or alloy do not completely dissolve in said second metal or alloy;
• and
• (g) cooling the infiltrated part to room temperature to form a substantially void-free precision molded article.