Patents Assigned to Crucible Materials Corporation
  • Patent number: 5435824
    Abstract: A martensitic hot work tool steel mold and die block article for use in the manufacture for molds for plastic injection molding, die casting die components, and other hot work tooling components. The article has a hardness within the range of 35 to 50 HRC, a minimum Charpy V-notch impact toughness of 3 foot pounds when heat treated to a hardness of 44 to 46 HRC and when tested both at 72.degree. F. and 600.degree. F. The article is an as hot-isostatically-compacted, fully dense, heat-treated mass of prealloyed particles which contain sulfur within the range of 0.05 to 0.30 weight percent. The hot work tool steel includes maraging and precipitation-hardening steels of this type.
    Type: Grant
    Filed: September 27, 1993
    Date of Patent: July 25, 1995
    Assignee: Crucible Materials Corporation
    Inventors: Carl J. Dorsch, Kenneth E. Pinnow, William Stasko
  • Patent number: 5344477
    Abstract: Prealloyed high-vanadium, cold work tool steel particles are provided for use in the powder-metallurgy production of tool steel articles. The particles are of a cold work tool steel alloy having an MC-type vanadium carbide dispersion of a carbide particle size substantially entirely less than 6 microns and in an amount of 18.5 to 34.0% by volume. The particles are produced by atomizing a molten tool steel alloy at a temperature above 2910.degree. F. and rapidly cooling the atomized alloy to form solidified particles therefrom. The particles have the MC-type vanadium carbide dispersion therein.
    Type: Grant
    Filed: March 4, 1993
    Date of Patent: September 6, 1994
    Assignee: Crucible Materials Corporation
    Inventors: William Stasko, Kenneth E. Pinnow
  • Patent number: 5282904
    Abstract: A permanent magnet of the neodymium-iron-boron type having improved corrosion resistance imparted by a combination of oxygen, carbon and nitrogen. Oxygen is provided in an amount equal to or greater than 0.6 weight percent in combination with carbon of 0.05-0.15 weight percent and nitrogen 0.15 weight percent maximum. Preferably, oxygen is within the range of 0.6-1.2% with carbon of 0.05-0.1% and nitrogen 0.02-0.15 weight percent or more preferably 0.04-0.08 weight percent. The magnet may be heated in an argon atmosphere and thereafter quenched in an atmosphere of either argon or nitrogen to further improve the corrosion resistance of the magnet.
    Type: Grant
    Filed: October 27, 1992
    Date of Patent: February 1, 1994
    Assignee: Crucible Materials Corporation
    Inventors: Andrew S. Kim, Floyd E. Camp, Edward J. Dulis
  • Patent number: 5238482
    Abstract: Prealloyed high-vanadium, cold work tool steel particles are provided for use in the powder-metallurgy production of tool steel articles. The particles are of a cold work tool steel alloy having an MC-type vanadium carbide dispersion of a carbide particle size substantially entirely less than 6 microns and in an amount of 18.5 to 34.0% by volume. The particles are produced by atomizing a molten tool steel alloy at a temperature above 2910.degree. F. and rapidly cooling the atomized alloy to form solidified particles therefrom. The particles have the MC-type vanadium carbide dispersion therein.
    Type: Grant
    Filed: May 22, 1991
    Date of Patent: August 24, 1993
    Assignee: Crucible Materials Corporation
    Inventors: William Stasko, Kenneth E. Pinnow
  • Patent number: 5213610
    Abstract: A method for atomizing a titanium-based material to particulates in a controlled atmosphere. In the method, titanium is skull melted in a crucible. The molten titanium-based material is transferred to a heated tundish. The molten titanium-based material may be stabilized in the heated tundish and then formed into a free-falling stream. The free-falling stream of the molten titanium-based material is impinged with an inert gas jet to atomize the molten titanium-based material. The method also includes cooling the atomized titanium-based material, and collecting the cooled atomized titanium-based material.
    Type: Grant
    Filed: January 6, 1992
    Date of Patent: May 25, 1993
    Assignee: Crucible Materials Corporation
    Inventors: Charles F. Yolton, Thomas Lizzi, John H. Moll
  • Patent number: 5162064
    Abstract: A permanent magnet of the neodymium-iron-boron type having improved corrosion resistance imparted by a combination of oxygen, carbon and nitrogen. Oxygen is provided in an amount equal to or greater than 0.6 weight percent in combination with carbon of 0.05-0.15 weight percent and nitrogen 0.15 weight percent maximum. Preferably, oxygen is within the range of 0.6-1.2% with carbon of 0.05-0.1% and nitrogen 0.02-0.15 weight percent or more preferably 0.04-0.08 weight percent. The magnet may be heated in an argon atmosphere and thereafter quenched in an atmosphere of either argon or nitrogen to further improve the corrosion resistance of the magnet.
    Type: Grant
    Filed: April 10, 1990
    Date of Patent: November 10, 1992
    Assignee: Crucible Materials Corporation
    Inventors: Andrew S. Kim, Floyd E. Camp, Edward J. Dulis
  • Patent number: 5127970
    Abstract: A method for improving the magnetic properties, particulaarly intrinsic coercivity, of particles of a permanent magnet alloy comprising a rare earth element, iron and boron. The method includes subjecting particles to a hydrogen atmosphere for a time at elevated temperature sufficient to hydride the particles. The hydrogen atmosphere is removed while maintaining the particles at the elevated temperature. Thereafter, while maintaining the particles at elevated temperature, the particles are subjected to a vacuum atmosphere for a time at the maintained elevated temperature sufficient to dehydride the particles. Thereafter, while maintaining the particles at the elevated temperature, they are again subjected to a hydrogen atmosphere for a time at the maintained elevated temperature sufficient to hydride the particles. The hydrogen atmosphere is removed while maintaining the particles at the elevated temperature.
    Type: Grant
    Filed: May 21, 1991
    Date of Patent: July 7, 1992
    Assignee: Crucible Materials Corporation
    Inventor: Andrew S. Kim
  • Patent number: 5113591
    Abstract: An apparatus for measuring the out-of-roundness of a cylindrical workpiece. The apparatus provides a plurality of parallel light beams in a direction perpendicular to a plane of the longitudinal axis of the cylindrical workpiece. The workpiece intersects a first portion of the light beams. A second portion of the light beams is obstructed. A third portion of the light beams passes between the cylindrical workpiece and the structure obstructing the second portion. A fourth portion of the light beams passes beyond a surface of the cylindrical workpiece opposite the surface in spaced apart relation with respect to the obstruction structure. The cylindrical workpiece is rotated about the longitudinal axis thereof. An electrical signal is provided representing a dimension of the first portion of the light beams intersected by the cylindrical object during rotation thereof.
    Type: Grant
    Filed: March 20, 1991
    Date of Patent: May 19, 1992
    Assignee: Crucible Materials Corporation
    Inventor: Eugene B. Connelly
  • Patent number: 5091020
    Abstract: A method for making rare earth element, iron and boron sintered permanent magnets, and a particle mixture for use therein. A hydrided 100% dross or particle mixture of virgin alloy particles and scrap alloy particles and/or dross alloy particles are dehydrided and sintered to produce a substantially fully dense article for use as a permanent magnet.
    Type: Grant
    Filed: November 20, 1990
    Date of Patent: February 25, 1992
    Assignee: Crucible Materials Corporation
    Inventor: Andrew S. Kim
  • Patent number: 5084091
    Abstract: Titanium is induction melted to produce a molten mass thereof and a water-cooled crucible having a nonoxidizing atmosphere and a bottom opening. The current to the coil used for induction melting is adjusted to produce a levitation effect on the molten mass in the crucible to prevent the molten mass from flowing out of the bottom opening. The molten mass is also maintained out-of-contact with the crucible by providing a solidified layer of titanium between the molten mass and the crucible. After production of the molten mass of titanium, the current to the induction coil is reduced to reduce the levitation effect and allow the molten mass to flow out of the bottom opening of the crucible as a free-falling stream of molten titanium. This stream is struck with an inert gas jet to atomize molten titanium to form spherical particles. Spherical particles are cooled to solidify them and are then collected.
    Type: Grant
    Filed: November 9, 1989
    Date of Patent: January 28, 1992
    Assignee: Crucible Materials Corporation
    Inventor: Charles F. Yolton
  • Patent number: 5055146
    Abstract: A permanent magnet alloy characterized by increased Curie temperature which is achieved by including nickel and cobalt in combination with at least one rare earth element neodymium and mischmetal in combination with iron and boron. Specifically, the alloy contains, in atomic percent, 10 to 20 mischmetal and/or neodymium, 2 to 30 nickel and/or cobalt, 2 to 14 boron and balance iron.
    Type: Grant
    Filed: June 9, 1989
    Date of Patent: October 8, 1991
    Assignee: Crucible Materials Corporation
    Inventors: Kalathur S. V. L. Narasimhan, Bao-Min Ma
  • Patent number: 5047205
    Abstract: A method for producing a compacted fully dense permanent magnet by providing a particle charge of a permanent magnet alloy composition from which the article is to be made and placing the charge in a cylindrical container having a generally axially positioned core with the charge surrounding the core within the container. The container and charge are heated to an elevated temperature and extruded to compact the charge to a substantially fully dense permanent magnet article.
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: September 10, 1991
    Assignee: Crucible Materials Corporation
    Inventors: Vijay K. Chandhok, Robert F. Krause, Bao-Min Ma, John J. DuPlessis
  • Patent number: 4999051
    Abstract: A system and method for atomizing a titanium-based material to particulates in a controlled atmosphere. The system includes a crucible for skull melting a titanium-based material. The molten titanium-based material is transferred to a tundish for receiving the molten titanium-based material. The tundish has a bottom portion with an aperture formed therein and is heated. A molten metal nozzle for forming the molten titanium-based material into a free-falling stream exiting from the tundish is provided, the molten metal nozzle being coaxially aligned with the aperture of the tundish. A baffle may be disposed in the tundish for stabilizing the free-falling stream of the molten titanium-based material. The molten titanium-based material is atomized by impinging the free-falling stream of the molten titanium-based material with an inert gas jet issuing from a gas nozzle.
    Type: Grant
    Filed: September 27, 1989
    Date of Patent: March 12, 1991
    Assignee: Crucible Materials Corporation
    Inventors: Charles F. Yolton, Thomas Lizzi, John H. Moll
  • Patent number: 4994109
    Abstract: A method for producing permanent magnet alloy particles suitable for use in producing bonded permanent magnets. A melt or molten mass of a permanent magnet alloy having at least one rare earth element, at least one transition element, preferably iron, and boron is produced. The melt is inert gas atomized to form spherical particles within the size range of 1 to 1000 microns. The particles are heat treated in a nonoxidizing atmosphere for a time at temperature to significantly increase the intrinsic coercivity of the particles without sintering the particles to substantially full density. Thereafter, the particles are separated to produce a discrete particle mass. The particles during heat treatment may be maintained in motion to prevent sintering thereof.
    Type: Grant
    Filed: May 5, 1989
    Date of Patent: February 19, 1991
    Assignee: Crucible Materials Corporation
    Inventors: Carol J. Willman, Edward J. Dulis, Francis S. Snyder
  • Patent number: 4990307
    Abstract: Particles for the production of permanent magents are obtained by producing an article having Ca and a rare earth oxide including at least Nd oxide. The article is heated to effect Ca rare earth oxide reduction. Thereafter, particles of -60 mesh or finer are formed from this article. Leaching of Ca from the particles is achieved by contacting the particles with an organic acid having at least 3 carbon atoms, preferably propionic or butanoic acid.
    Type: Grant
    Filed: March 22, 1988
    Date of Patent: February 5, 1991
    Assignee: Crucible Materials Corporation
    Inventor: Floyd E. Camp
  • Patent number: 4971756
    Abstract: Producing a die for use in compacting permanent magnet alloy powder by placing a quantity of a magnetic or nonmagnetic alloy, which may be stainless steel, cobalt- or nickel-base, or a magnetic or nonmagnetic mixture of one of these alloys and carbide particles in a container, heating the particles to an elevated temperature and hot-isostatically compacting the particles at the elevated temperature to obtain a fully dense die blank and forming a die cavity in the die blank. Carbide particles may be mixed with the alloy particles. The die blank may have an exterior cladding of stainless steel.
    Type: Grant
    Filed: May 12, 1989
    Date of Patent: November 20, 1990
    Assignee: Crucible Materials Corporation
    Inventor: John J. DuPlessis
  • Patent number: 4942922
    Abstract: Welded ferritic stainless steel tubing having high resistance to hydrogen embrittlement particularly adapted for use in heat exchangers handling chemical media containing hydrogen sulfide or nascent hydrogen and in cathodically protected heat exchangers. The ferritic stainless steel of the welded tubing consists essentially of, in weight percent, carbon at least 0.002, nitrogen at least 0.002, carbon plus nitrogen 0.02 max. and preferably 0.01 to 0.02, chromium 23 to 28, preferably 25 to 28, manganese up to 1, preferably up to 0.5, nickel 1 to 4, silicon up to 1, preferably up to 0.5, phosphorus up to 0.04, sulfur up to 0.02, preferably up to 0.005, molybdenum 2 to 5, preferably 2 to 4, aluminum up to 0.1, columbium 0.60 max. with columbium being at least equal to eight times carbon plus nitrogen, and the balance iron and incidental impurities.
    Type: Grant
    Filed: October 18, 1988
    Date of Patent: July 24, 1990
    Assignee: Crucible Materials Corporation
    Inventors: Lawrence S. Redmerski, Kenneth E. Pinnow, John J. Eckenrod
  • Patent number: 4933142
    Abstract: A low carbon plus nitrogen, free-machining, austenitic stainless steel having improved machinability and excellent corrosion resistance. The steel composition in weight percent is carbon plus nitrogen up to about 0.06, chromium 16 to 20, nickel 6 to 14, manganese up to 0.60, sulfur 0.15 to 0.50, silicon up to about 1, phosphorus up to about 0.20, molybdenum up to about 1 and balance iron.
    Type: Grant
    Filed: February 3, 1989
    Date of Patent: June 12, 1990
    Assignee: Crucible Materials Corporation
    Inventors: Walter T. Haswell, Jr., Kenneth E. Pinnow, John J. Eckenrod, Geoffrey O. Rhodes
  • Patent number: 4915891
    Abstract: A method for producing a noncircular magnet having asymmetric magnetic properties along axes thereof. A particle charge of composition from which the magnet is to be produced is placed in a container, heated and extruded within the container to compact the particle charge to substantially full density. The particle charge may include at least one rare earth element. The particle charge may be extruded through a noncircular extrusion die, specifically a rectangular die.
    Type: Grant
    Filed: November 27, 1987
    Date of Patent: April 10, 1990
    Assignee: Crucible Materials Corporation
    Inventors: Vijay K. Chandhok, Bao-Min Ma
  • Patent number: 4902360
    Abstract: A permanent magnet alloy consisting essentially of R.sub.2 Fe.sub.14 B, wherein, R is a combination of rare earth elements consisting essentially of, in atomic percent, neodymium 3 to 11 and balance holmium. The alloy may include optional additions of the rare earth elements gadolinium up to 10%, terbium up to 15%, dysprosium up to 16%, erbium up to 18% and thulium up to 12%.
    Type: Grant
    Filed: October 28, 1988
    Date of Patent: February 20, 1990
    Assignee: Crucible Materials Corporation
    Inventors: Bao-Min Ma, Kalathur S. V. L. Narasimhan