Abstract: A metal matrix composite (MMC) material that is castable, or can be rendered castable, is melted and cast into a mold or crucible, and at least a portion of the plurality of reinforcement bodies is permitted to at least partially settle out of their suspension in the molten matrix metal. The casting is solidified, and the sparsely loaded supernatant is separated from the zone of the casting containing the sediment—either by cutting, sawing, etc., or by decanting the supernatant when the casting was still in a molten condition. In a preferred embodiment, during the settling and/or the solidification process, mechanical energy, such as in the form of oscillations, is applied to the MMC melt. The applied energy permits the reinforcement bodies to nestle and pack more efficiently, thereby increasing their volumetric loading in the cast composite.

Abstract: A method for producing a metal matrix composite having improved properties includes the step of forming a sintered ceramic preform including a network of uniformly distributed ceramic particles having a particle size of 1 micron or less and being bonded together at their points of contact by sintering. After sintering to form a preform, the preform is placed in a mold and infiltrated with molten metal. The molten metal is then solidified to form a shaped body. This shaped body is then subjected to sufficient strain to eliminate at least 50% and preferably 80% of the bonds in the network. The shaped body is then subjected to a metal forming step such as wrought or semisolid forming.

Abstract: A light-weight metal matrix composite includes a bimodal distribution of ceramic particles which are uniformly distributed within a metal or alloy matrix. The bimodal distribution includes a first component of ceramic particles having an average particle size of less than 1 micron and a second component of ceramic particles having an average particle size of about 5 to 15 microns. The metal matrix composite includes from about 15 to 30% by weight of the first component and from about 2.5 to about 10% by weight of the second component. At least 80% of the particles in the first component are uniformly distributed so that the particle spacing does not exceed 3 times the diameter of the largest cross sectional dimension of the particles in the first component and at least 80% of the ceramic particles in the second component are uniformly distributed so that the inner particle spacing does not exceed 3 times the diameter of the largest cross sectional dimension of the particles in the second component.

Abstract: Metal-matrix composites and methods for producing these composites are provided. The manufacturing methods include providing a ceramic preform having a uniform distribution of ceramic particles sintered to one another. The particles include an average particle size of no greater than about 3 microns, and at least one half of the volume of the preform is occupied by porosity. The preform is then disposed into a mold and contacted by molten metal. The molten metal is then forced into the pores of the preform and permitted to solidify to form a solid metal-matrix composite. This composite is machinable with a high-speed steel (HSS) bit for greater than about 1 minute without excessive wear occurring to the bit. This invention preferably employs metal-matrixes including Al, Li, Be, Pb, He, Au, Sn, Mg, Ti, Cu, and Zn. Preferred ceramics include oxides, borides, nitrides, carbides, carbon, or a mixture thereof. Inert gas pressures of less than about 3,000 psi can be used to easily infiltrate the preforms.

Abstract: Metal-matrix composites and methods for producing these composites are provided. The manufacturing methods include providing a ceramic preform having a uniform distribution of ceramic particles sintered to one another. The particles include an average particle size of no greater than about 3 microns, and at least one half of the volume of the preform is occupied by porosity. The preform is then disposed into a mold and contacted by molten metal. The molten metal is then forced into the pores of the preform and permitted to solidify to form a solid metal-matrix composite. This composite is machinable with a high-speed steel (HSS) bit for greater than about 1 minute without excessive wear occurring to the bit. This invention preferably employs metal-matrixes including Al, Li, Be, Pb, He, Au, Sn, Mg, Ti, Cu, and Zn. Preferred ceramics include oxides, borides, nitrides, carbides, carbon, or a mixture thereof. Inert gas pressures of less than about 3,000 psi can be used to easily infiltrate the preforms.

Abstract: Composites of materials in which the matrix material does not spontaneously or readily wet the disperse phase and in which the volume fraction of the disperse phase is less than that formed in a packed bed of dispersate particles can be made effectively by an indirect method of infiltrating a packed bed of dispersate particles, using pressure or other mechanical force as needed to overcome poor wetting and form an intermediate concentrated composite. The concentrated composite is then mixed with additional matrix-forming material to produce the finally desired composite. The technique is particularly valuable for composites with ceramic dispersates and metal or alloy matrixes.

Abstract: This invention relates generally to the fabrication of materials for use as tools in various applications. Specific emphasis is placed upon certain ceramic matrix composite materials and metal matrix composite materials for use as tools as well as certain ceramic matrix composite and/or metal matrix composite coatings on substrate materials, also for use as tools. This invention makes specific reference to a number of different materials for use as tools in the molding of thermoplastic materials (e.g., polymers, plastics, ceramics, glasses, metals) with particular emphasis being directed to the thermoplastic molding of plastics or polymers.