초록 ▼

A precision molded article, such as a die cavity, is made by combining granules of a refractory and granules of a first metal or alloy which has a homogeneous crystalline appearance at a temperature below its melting point and has a lower Rockwell Hardness than the refractory, mixing the granules wi

A precision molded article, such as a die cavity, is made by combining granules of a refractory and granules of a first metal or alloy which has a homogeneous crystalline appearance at a temperature below its melting point and has a lower Rockwell Hardness than the refractory, mixing the granules with a heat fugitive organic binder, molding the granule-binder mixture into a green molded preform, thermally degrading and removing essentially all the binder to form a skeletal preform, and infiltrating the preform with a second metal or alloy which will wet the first metal or alloy and has a lower Rockwell Hardness than the first metal or alloy, thereby forming a molded article having refractory granules fully enveloped within a single skeleton of the first metal or alloy, the refractory granules and skeleton of first metal being surrounded by layers or matrices of softer metals.

대표청구항 ▼

A metal composite article comprising: (a) less than about 15 percent of the volume of said article of granules of a refractory of about 1 to about 100 micrometers mean diameter, said refractory being (i) metal carbide, boride, oxide, silicide, or nitride, (ii) metal selected from the group consistin

A metal composite article comprising: (a) less than about 15 percent of the volume of said article of granules of a refractory of about 1 to about 100 micrometers mean diameter, said refractory being (i) metal carbide, boride, oxide, silicide, or nitride, (ii) metal selected from the group consisting of tungsten, molybdenum, tantalum, niobium, vanadium, and titanium, or (iii) combinations thereof; (b) a monolithic skeleton comprising about 35 to about 70 percent of the volume of said article of a solid first metal or alloy which has a homogeneous crystalline appearance at a temperature below its melting point when viewed under an optical microscope and has lower Rockwell hardness than said refractory, said first metal or alloy fully enveloping said refractory granules, the latter being uniformly dispersed in said skeleton; and (c) about 15 to about 50 percent of the volume of said article of a continuous metallic phase occupying the connected porosity in said skeleton, said continuous phase comprising a solid second metal or alloy which wets said skeleton, has a Rockwell hardness less than or equal to the Rockwell hardness of said first metal or alloy, and has a melting point below the melting point of said first metal or alloy; said article thereby comprising two intermeshed matrices and being substantially free of voids.