Patents by Inventor Hiroyoshi Suenaga

Hiroyoshi Suenaga has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5478657
    Abstract: The object of the present invention is to provide titanium discs to be used as high-density read-while-write magnetic discs. Further object of the present invention is to provide said titanium discs coated with a non-magnetic plated layer.Titanium discs to be used as magnetic discs which satisfy the above object have the following structures: A titanium disc to be used as magnetic disc having the mean height of the peaks from the center line, R.sub.a, of 0.0002 .mu.m to 0.0060 .mu.m and pits on its surface of 25 .mu.m or less in diameter or 5 .mu.m or less in depth. Further, said titanium disc to be used as a magnetic disc is coated with a non-magnetic plated layer with a thickness of 0.09 .mu.m to 5 .mu.m. Moreover, a titanium disc that is most suitable to be used as a magnetic disc is the titanium disc provided with a plated layer of 30/100 or less in a knife-cut peeling test.
    Type: Grant
    Filed: June 6, 1994
    Date of Patent: December 26, 1995
    Assignees: NKK Corporation, Fuji Electric Co., Ltd.
    Inventors: Hiroyoshi Suenaga, Iwao Ida, Hitoshi Nagashima, Masanori Ohmura, Naoto Kohshiro, Noboru Kurata
  • Patent number: 5360677
    Abstract: A magnetic disk substrate having a composition wherein (V/13)+(Fe/20)+(Cr/17)+(Ni/31)+(Co/23) are no greater than 0.010%, Rem+Si+B+W are no greater than 0.015% (where Rem denotes rare earth metals), 0+2N+0.75C are no less than 0.03% and no greater than 0.5%, and the remainder consists substantially of Ti, all % being weight %.
    Type: Grant
    Filed: January 13, 1993
    Date of Patent: November 1, 1994
    Assignee: NKK Corporation
    Inventors: Hideaki Fukai, Hiroyoshi Suenaga, Kuninori Minakawa, Shinichiro Otaka, Masahiko Naoe
  • Patent number: 5221459
    Abstract: A method of manufacturing a magnetic disk substrate made of titanium, in which chemical etching is performed on a titanium disk for magnetic disk substrate, thereby removing a surface portion thereof having a thickness of at least 2 nm, and the new surface of the titanium disk, formed by the chemical etching, is anodized, thereby forming anodized film on the titanium disk.
    Type: Grant
    Filed: April 24, 1992
    Date of Patent: June 22, 1993
    Assignee: NKK Corporation
    Inventors: Yoko Okano, Hiroyoshi Suenaga, Toshio Sakiyama, Kenji Morita, Masanori Ohmura, Iwao Ida, Hitoshi Nagashima
  • Patent number: 5188677
    Abstract: A method of manufacturing a titanium alloy magnetic disk substrate comprising (a) cold-rolling an alloy plate at a rolling ratio of no less than 30%, the alloy plate comprising 0.5 wt. % to 1.0 wt. % of Mo and containing oxygen, nitrogen and carbon in amounts such that O+2N+0.75C is from 0.03 wt. % to 0.5 wt. % of the titanium alloy, and the balance being Ti, wherein O is the wt. % of oxygen, N is the wt. % of nitrogen and C is the wt. % of C to form a magnetic disk substrate material and then (b) thermal-flattening the magnetic substrate material from step (a) under a condition defined as follows:500.ltoreq.T.ltoreq.-(150/11).multidot.t+7,850/11 1.ltoreq.twhere T represents a thermal-flattening temperature in .degree.C., and t represents a thermal-flattening time in hours.
    Type: Grant
    Filed: June 21, 1991
    Date of Patent: February 23, 1993
    Assignee: NKK Corporation
    Inventors: Hideaki Fukai, Hiroyoshi Suenaga, Kuninori Minakawa
  • Patent number: 5159787
    Abstract: A method for lapping two surfaces of a titanium disk comprises inserting loosely a titanium disk to be lapped into an opening in a disk-type carrier, the carrier rotating and revolving between an upper surface plate and a lower surface plate which are held in parallel with each other and which applies lapping pressure to the titanium disk, feeding abrasives between the surface plates and the titanium disk and satisfying the following relationship between thickness t (mm) of the titanium disk and thickness T (mm) of the carrier:0.025 exp (t+1.5).ltoreq.T.ltoreq.0.
    Type: Grant
    Filed: September 30, 1991
    Date of Patent: November 3, 1992
    Assignee: NKK Corporation
    Inventors: Hiroyoshi Suenaga, Takeshi Ito, Masakuni Takagi, Hiroyoshi Takeuchi, Hideaki Fukai, Kuninori Minakawa
  • Patent number: 5136819
    Abstract: According to a mirror surface polishing process of the present invention, it is possible to produce Ti-made magnetic disc substrate which have the excellent flatness degree and surface roughness in that the average roughness is not more than 0.05 .mu.m and the flatness degree of the outer periphery is not more than 0.15 .mu.m.
    Type: Grant
    Filed: February 1, 1991
    Date of Patent: August 11, 1992
    Inventors: Masakuni Takagi, Hiroyoshi Takeuchi, Hideaki Fukai, Toshio Sakiyama, Hiroyoshi Suenaga, Kuninori Minakawa
  • Patent number: 5131995
    Abstract: After the surface roughness of a titanium substrate is set to be R.sub.max .ltoreq.0.08 .mu.m, a hardened layer having a hardness of H.sub.v .gtoreq.250 is formed thereon to have a thickness of 50 to 250 .mu.m by sputtering, thereby manufacturing a titanium magnetic disk substrate.
    Type: Grant
    Filed: February 28, 1991
    Date of Patent: July 21, 1992
    Assignee: NKK Corporation
    Inventors: Hiroyoshi Suenaga, Hideaki Fukai, Toshio Sakiyama, Kuninori Minakawa
  • Patent number: 5120615
    Abstract: A magnetic disk substrate composition 0.5 wt % to 1.0 wt % of Mo, 0.03 wt % to 0.5 wt % of O+2N+0.75C, and a balance of Ti. The alloy sheet having a composition of above range is cold-rolled at a rolling ratio of 30% or more to form a magnetic disk substrate material, and the material is thermal-flattened under the following condition:500.ltoreq.T.ltoreq.-(150/11).multidot.t+7850/111.ltoreq.twhere T represents a thermal-flattening temperature (.degree.C.), and t represents a thermal-flattening time (houre), thereby obtaining a magnetic disk substrate having the average grain size of 30 .mu.m or less.
    Type: Grant
    Filed: June 12, 1990
    Date of Patent: June 9, 1992
    Assignee: NKK Corporation
    Inventors: Hideaki Fukai, Hiroyoshi Suenaga, Kuninori Minakawa
  • Patent number: 5060845
    Abstract: A method for manufacturing titanium clad steel plate by forming a slab assembly having an alloy steel substrate, a titanium metal or alloy cladding on said substrate and a Ni-Cr alloy foil or film having opposed surfaces between said alloy steel and said cladding. The Ni-Cr alloy foil or film has one surface in surface contact with the cladding and the opposed surface in surface contact with the alloy steel substrate. The Ni-Cr alloy contains 32.5 to 40 wt. % Cr and 55 to 65 wt. % Ni. The slab assembly is heated at a temperature of 850.degree. to 1010.degree. C. The heated slab assembly is hot rolled with a reduction ratio of 30% or more to form the titanium clad steel plate.
    Type: Grant
    Filed: June 4, 1990
    Date of Patent: October 29, 1991
    Assignee: NKK Corporation
    Inventors: Hiroyoshi Suenaga, Misao Ishikawa, Kuninori Minakawa
  • Patent number: 4990362
    Abstract: Titanium magnetic disk substrates are manufactured by preparing a base by stripping not less than 5 .mu.m from the surface layer of a titanium cold-rolled plate, and then forming a film of not less than 5 .mu.m consisting of 1 or more non-magnetic transition metal elements belonging to Groups IVA, VA, VIA, VIIA and VIIIA of the Periodic Table, on the surface of this base.
    Type: Grant
    Filed: February 16, 1990
    Date of Patent: February 5, 1991
    Assignee: NKK Corporation
    Inventors: Hiroshi Kibe, Hideaki Fukai, Hiroyoshi Suenaga
  • Patent number: 4944914
    Abstract: The invention provides a titanium alloy having improved superplastic forming characteristics and mechanical characteristics. A titanium alloy having superplastic forming characteristics consisting essentially of about 5.5 to 6.75 wt. % Al, 3.5 to 4.5 wt. % V, 0.01 to 0.2 wt. % O, 0.85 to 3.15 wt. % Fe, 0.85 to 3.25 wt. % Mo, with 2.times.Fe wt. %+Mo wt. % being from 3 to 8, and balance titanium; said alloy containing .alpha.-crystals having a grain size below about 6 .mu.m in diameter. The Fe and Mo act as .beta.-stabilizing elements and contributing elements to lowering the beta transus and to the improvement of the superplastic characteristics.
    Type: Grant
    Filed: November 30, 1989
    Date of Patent: July 31, 1990
    Assignee: NKK Corporation
    Inventors: Atsushi Ogawa, Hiroyoshi Suenaga, Kuninori Minakawa
  • Patent number: 4799975
    Abstract: A .beta. type titanium alloy material is passed through processes and heating treatments of cold working--intermediate solution treatment--final cold working--final solution treatment--aging. In this process, a structure, which has been provided with strains by the cold working performed prior to the final cold working, will be changed into a recrystallized structure by carrying out the intermediate solution treatment, where uniform and fine micro substructure of dislocations, remain with grains. If such an intermediate solution-treated material is processed with a slight cold working by the final cold working and further with the solution treatment, only a recovery phenomenon progresses, and it is possible to provide such a micro substructure containing more uniform and finer dislocation network not only in grains but also in grain boundaries. Therefore, in the aging, expedition of precipitation and uniform distribution of .alpha.
    Type: Grant
    Filed: September 22, 1987
    Date of Patent: January 24, 1989
    Assignees: Nippon Kokan Kabushiki Kaisha, Nippon Mining Co., Ltd.
    Inventors: Chiaki Ouchi, Yohji Kohsaka, Hiroyoshi Suenaga, Hideo Sakuyama, Hideo Takatori
  • Patent number: 4694985
    Abstract: For producing titanium clad steel plates by hot rolling, oxide of Mo or V is used as an intermediate material, and a slab assembly is formed with ferrous bases and titanium cladding materials. At least one side of cladding surfaces of the bases and the cladding materials is coated with an oxide of Mo or V of 20 to 300 g/m.sup.2, and an interior of the slab assembly is air-discharged less than 10.sup.-1 torr, and the slab assembly is heated at temperatures between a melting point of the employed oxide plus 50.degree. C. and 1050.degree. C. and undertaken with hot rolling.
    Type: Grant
    Filed: August 1, 1986
    Date of Patent: September 22, 1987
    Assignee: Nippon Kokan Kabushiki Kaisha
    Inventors: Chiaki Ouchi, Masakazu Niikura, Hiroyoshi Suenaga
  • Patent number: 4675055
    Abstract: A method for producing Ti alloy plates, comprising heating an .alpha.+.beta. Ti alloy ingot to a temperature within the .alpha.+.beta. two phase range, forging or rolling said heated alloy ingot to reduce it more than 30% whereby strain energy accumulates in said ingot as it is being reduced, and reheating said reduced ingot containing said accumulated strain energy to a temperature of the .alpha.+.beta. phase range and then hot rolling said reheated reduced ingot so that it is further reduced in an amount more than an additional 30% whereby said accumulated strain energy accelerates recrystallization during said hot rolling to produce a uniform alloy structure, said heating and reheating being carried out in an atmosphere having not more than 0.02 atm oxygen partial pressure.
    Type: Grant
    Filed: May 1, 1985
    Date of Patent: June 23, 1987
    Assignees: Nippon Kokan Kabushiki Kaisha, Nippon Mining Co., Ltd.
    Inventors: Chiaki Ouchi, Hiroyoshi Suenaga, Hideo Sakuyama, Michio Hanai, Ichiroh Sawamura
  • Patent number: 4581077
    Abstract: A method of manufacturing a rolled titanium alloy sheet comprises breaking down an .alpha. or .alpha.+.beta. titanium alloy ingot into a slab, working the slab in sequential stages of(A) cross rolling the slab in the .alpha.+.beta. region under a condition of a reduction ratio of at least 1.2 and a cross rolling ratio of 0.6 to 1.4,(B) annealing the workpiece for recrystallization at a temperature 20.degree. to 100.degree. C., preferably 20.degree. to 70.degree. C., below the .beta.-transus of the alloy, and(C) further cross rolling it in the .alpha.+.beta. region under a condition of a reduction ratio of at least 1.6 and a cross rolling ratio of 0.6 to 1.4,and thereafter heat treating the rolled workpiece for annealing, solution treatment and aging or the like, depending on the intended use of the product. The method may include an additional stage (D) of repeating stages (B) and (C) at least once each. The ingot breakdown is preferably carried out by forging or rolling at a temperature of the two-phase .
    Type: Grant
    Filed: April 22, 1985
    Date of Patent: April 8, 1986
    Assignee: Nippon Mining Co., Ltd.
    Inventors: Hideo Sakuyama, Ichiro Sawamura, Michio Hanaki, Chiaki Ouchi, Hiroyoshi Suenaga
  • Patent number: 4417493
    Abstract: A method for cutting off a steel plate, wherein the steel plate is heated to a temperature within the range of from 950.degree. to 1,400.degree. C. at the time of cutting off the steel plate; the heated steel plate is placed on a roller table extending horizontally and positioned at a desired position so that a side edge of the heated steel plate is in contact with the cutting edge of at least one cutting knife on the roller table. The cutting edge angle of the cutting knife is within the range of from 10.degree. to 45.degree.. The cutting knife is then moved horizontally relative to the heated steel plate, in the width direction or the length direction of the steel plate, at a cutting speed of from 10 to 1000 cm/minute, thereby cutting off the steel plate by the cutting knife in the horizontal direction.
    Type: Grant
    Filed: April 7, 1981
    Date of Patent: November 29, 1983
    Assignee: Nippon Kokan Kabushiki Kaisha
    Inventors: Chiaki Ohuchi, Yoji Kohsaka, Hiroyoshi Suenaga