# US 5,702,542 A · Machinable metal-matrix composite > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,702,542 A - Document ID: US5702542A - Status: Granted - Kind: A - Application number: 08/574,039 - Filed: 1995-12-18 - Granted: 1997-12-30 - Earliest claimed: 1993-03-26 - Inventors: Alexander M. Brown; Eric M. Klier - Web page: https://patentgrep.com/patent/US5702542A ## CPC - B22D 19/14: the objects being filamentary or particulate in form (making alloys containing fibres or filaments by contacting the fibres or filaments with molten metal C22C47/08) - B22F 3/26: Impregnating {(making ferrous alloys by impregnation C22C33/0242)} - C22C 1/1021: {the preform being ceramic} - C22C 1/1084: {by mechanical alloying (blending, milling)} - C22C 32/00: Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ - C22C 47/06: by forming the fibres or filaments into a preformed structure, e.g. using a temporary binder to form a mat-like element - Y10T 428/12576: Boride, carbide or nitride component - Y10T 428/12611: Oxide-containing component - B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22) - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - C22C: ALLOYS (treatment of alloys C21D, C22F) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## 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. ## Claims ### Claim 1 A metal-matrix composite comprising a uniform distribution of calcined ceramic particles having an average particle size no greater than about 1 micron and a metal or alloy substantially uniformly distributed with said ceramic particles, in which said ceramic particles comprise at least 15 volume % of the metal-matrix and said metal-matrix composite being machineable with a high-speed steel (HSS) bit for greater than about 1 minute without excessive wear to said bit. ### Claim 2 A metal-matrix composite comprising a uniform distribution of calcined ceramic particles having an average particle size no greater than about 1 micron, and a metal or alloy substantially uniformly distributed with said ceramic particles in which said ceramic particles comprise at least about 15 volume % of the metal-matrix and wherein at least 80% of said ceramic particles are uniformly distributed on a scale of three times the particle size. ### Claim 3 (depends on 2) A metal-matrix composite according to claim 2 wherein at least 90% of said ceramic particles are uniformly distributed on a scale of twice the particle size. ### Claim 4 (depends on 3) A metal-matrix composite according to claim 3 in which said metal-matrixx composite is machineable a steel (HSS) bit for than about 1 minute without excessive wear to said bit. ### Claim 5 (depends on 4) The metal-matrix composite of claim 4, wherein said ceramic particles have an aspect ratio of no greater than about 3:1. ### Claim 6 (depends on 5) The metal-matrix composite of claim 5, wherein said ceramic particles have an aspect ratio of no greater than about 2:1. ### Claim 7 (depends on 2) The metal-matrix composite of claim 2, wherein said composite has a tensile modulus which is at least about 30 to 200% greater than the tensile modulus of said metal. ### Claim 8 (depends on 2) The metal-matrix composite of claim 2, wherein said composite has a tensile strength of at least twice that of said metal, and retains said tensile strength at temperatures up to about one half the melting point of said metal. ### Claim 9 (depends on 2) The metal-matrix composite of claim 2, wherein said metal-ceramic composite has a plastic elongation of at least about 30% of the plastic elongation for said metal. ### Claim 10 (depends on 3) The metal-matrix composite of claim 3, wherein said composite has a tensile strength of at least twice that of said metal, and retains said tensile strength at temperatures up to about one half the melting point of said metal. ### Claim 11 (depends on 10) The metal-matrix composite according to claim 10 in which said metal-matrix composite is machineable with a high-speed steel bit for greater than about 1 minute without excessive wear to said bit. ### Claim 12 (depends on 11) The metal-matrix composite of claim 11, wherein said composite has a tensile modulus which is at least about 30 to 200% greater than the tensile modulus of said metal. ### Claim 13 A metal-matrix composite comprising a uniform distribution of calcined ceramic particles having an average particle size no greater than about 1 micron, and a metal or alloy substantially uniformly distributed with said ceramic particles, in which said ceramic particles comprise at least about 15 volume % of the metal-matrix and in which said ceramic particles are thermally stable in the molten metal-matrix. ### Claim 14 (depends on 13) A metal-matrix composite according to claim 13, wherein said ceramic particles are chemically stable in the molten metal or alloy. ### Claim 15 (depends on 13) A metal-matrix composite according to claim 13, in which said ceramic particles comprising: an oxide, boride, nitride, carbide, carbon, or combination thereof; and a metal or alloy uniformly distributed with said ceramic particles, said metal or alloy comprising Al, Li, Be, Pb, Ag, Au, Sn, Mg, Ti, Cu, Zn or a mixture thereof.