Nitriding Patents (Class 148/238)
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Patent number: 7601296Abstract: A method of forming a sputtering target and other metal articles having controlled oxygen and nitrogen content levels and the articles so formed are described. The method includes surface-nitriding a deoxidized metal powder and further includes consolidating the powder by a powder metallurgy technique. Preferred metal powders include, but are not limited to, valve metals, including tantalum, niobium, and alloys thereof.Type: GrantFiled: May 10, 2006Date of Patent: October 13, 2009Assignee: Cabot CorporationInventors: Christopher A. Michaluk, Shi Yuan, James Maguire
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Publication number: 20090200177Abstract: A method and process for at least partially forming a medical device that is at least partially formed of a novel metal alloy which improves the physical properties of the medical device.Type: ApplicationFiled: April 24, 2009Publication date: August 13, 2009Inventors: JOSEPH G. FURST, Udayan Patel, Raymond W. Buckman, JR.
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Publication number: 20090180240Abstract: The present invention relates to valve metal particles uniformly containing nitrogen and a method for preparing the same, and a valve metal green pellet and a sintered pellet made from the particles, and an electrolytic capacitor anode. The present invention provides valve metal particles uniformly containing nitrogen, wherein the difference ratio of nitrogen contents of particles is 20% or less. The present invention provides a process for preparing said valve metal particles uniformly containing nitrogen, wherein the raw material particles of the valve metal were heated in a nitrogen-containing gas at a temperature of 200° C. or less for 2 hours or more. The present invention also provides a valve metal green pellet made from said valve metal particles. The present invention also provides a valve metal sintered pellet.Type: ApplicationFiled: October 14, 2008Publication date: July 16, 2009Inventors: Bin LI, Luntao PAN, Aiguo ZHENG, Yuezhong MA, Yuewei CHENG, Xuecheng DONG, Xueqing ZHANG, Zhidao WANG, Baojun ZHU
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Patent number: 7556699Abstract: A method of nitriding a metal includes transforming a surface region of a generally nitrogen-free metal into a nitrogen-containing solid solution surface region. A first heating process heats the surface region at a first temperature in the presence of a nitrogen gas partial pressure to form a nitrogen-charged surface portion on the surface region. A second heating process heats the surface region and nitrogen-charged surface portion at a second temperature for a predetermined time to interstitially diffuse nitrogen from the nitrogen-charged surface portion a depth into the surface region. Coincident with the second heating process, an ionized inert or reducing gas removes the nitrogen-charged surface portion. The resulting nitrogen-containing solid solution surface region has a gradual transition in nitrogen concentration.Type: GrantFiled: June 17, 2004Date of Patent: July 7, 2009Inventors: Clark VanTine Cooper, Krassimir G. Marchev, Bill C. Giessen
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Patent number: 7438769Abstract: A method for diffusing titanium and nitride into a base material having a coating thereon using conventional surface treatments or coatings. The method generally includes the steps of providing a base material having a coating thereon; providing a salt bath which includes sodium dioxide and a salt selected from the group consisting of sodium cyanate and potassium cyanate; dispersing metallic titanium formed by electrolysis of a titanium compound in the bath; heating the salt bath to a temperature ranging from about 430° C. to about 670° C.; and soaking the base material in the salt bath for a time of from about 10 minutes to about 24 hours. In accordance with another aspect of the present invention, titanium and nitride may be diffused into a base material without a coating. The treated base material may further be treated with conventional surface treatments or coatings.Type: GrantFiled: April 18, 2006Date of Patent: October 21, 2008Inventors: Philos Jongho Ko, Bongsub Samuel Ko
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Patent number: 7344675Abstract: A method of producing high strength nanophase metal alloy powder by cryomilling metal powder under conditions which cause the formation of intrinsic nitrides, and of producing high strength metal articles by subjecting the nitrided cryomilled powder to thermo-mechanical processing. The intrinsic nitrides present within the alloy significantly reduce grain growth during thermo-mechanical processing, resulting in formed metal products of high strength and improved ductility.Type: GrantFiled: March 12, 2003Date of Patent: March 18, 2008Assignee: The Boeing CompanyInventors: Thomas J. Van Daam, Clifford C. Bampton
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Patent number: 6929757Abstract: A magnetorheological fluid containing magnetorheological particles which are resistant to oxidation having regions rich in diffused nitrogen located therein and a method for producing such magnetorheological fluid.Type: GrantFiled: August 25, 2003Date of Patent: August 16, 2005Assignee: General Motors CorporationInventors: John C. Ulicny, Yang T. Cheng
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Publication number: 20040253448Abstract: The present invention relates to a manufacturing method of a material for vacuum device used in a vacuum apparatus that generates ultra-high vacuum and performs processing.Type: ApplicationFiled: June 8, 2004Publication date: December 16, 2004Applicant: VACLAB, INC.Inventor: Fumio Watanabe
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Patent number: 6830700Abstract: A method and device for removing particulate matter from a liquid medium, especially a molten salt bath. The structure includes a device for capturing and removing particulate matter from a liquid medium. In operation, the device is inserted into the liquid having the particulate matter, with a particulate matter collector in the particle collecting position. An agitator circulates the liquid having the particulate matter therein. A portion of the particulate matter is collected in the particulate matter collector during the circulation. Thereafter, the circulation is ceased and the device is removed from the liquid with the particulate matter in the particulate matter collector. The device is moved to a discharge position, and the particulate matter collector is moved to a particle discharge position to discharge the particulate matter.Type: GrantFiled: July 8, 2003Date of Patent: December 14, 2004Assignee: Kolene CorporationInventor: Richard Michael Kitchen
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Publication number: 20040007292Abstract: A nitriding method includes the steps of nitriding an object held under a nitriding gas atmosphere in a sealed furnace and applying vibration energy to one or both of the nitriding gas and the object W to facilitate nitriding. A nitriding apparatus includes a nitriding furnace for holding an object W to be nitrided in a sealed manner, means 30 for supplying a nitriding gas to the furnace, and means 2 for applying vibration to the atmosphere gas in the furnace 1 to faciliate nitriding. According to the method or apparatus, nitriding-resistant or complex-shaped materials can be nitrided at high efficiency and a nitrided layer can be formed at a lower temperature for a shorter time as compared with conventional processes.Type: ApplicationFiled: March 21, 2003Publication date: January 15, 2004Inventors: Hideto Fujita, Yoshiyuki Fujita, Ryoji Fujino, Yasutaka Ogawa
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Patent number: 6627856Abstract: Disclosed is a moveable heat exchanger for use with a high temperature chamber, such as for instance a nitriding furnace. The heat exchanger is between a first position external to the furnace, and a second position in which the heat exchanger projects substantially into the furnace through an opening in a wall surface of the furnace. In use, the heat exchanger is in the first position during a high temperature portion of a process and is in the second position during a cooling portion subsequent to the high temperature portion of the process. The heat exchanger sealingly engages the wall surface about its periphery to prevent the exchange of atmospheric components in either direction between the interior of the furnace and the outside.Type: GrantFiled: December 26, 2001Date of Patent: September 30, 2003Assignee: Nitrex Metal Inc.Inventors: Michel J. Korwin, Janusz Szymborski
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Patent number: 6589368Abstract: The present invention provides a refractory-metal-based alloy material having a remarkably enhanced toughness and strength, by internally nitriding a nitride-forming metal element incorporated as a solid solution into an alloy worked piece, which has a parent phase consisting of one element selecting from Mo, W and Cr, at a temperature equal to or lower than a recrystallization upper limit temperature of the worked piece to dispersedly yield ultra-fine nitride particles to the worked piece and thereby raise a recrystallization lower limit temperature of the worked piece, and then subjecting the internally nitrided worked piece to a second nitriding treatment at a temperature equal to or more than the raised recrystallization lower limit temperature, wherein at least in the surface region of the worked piece has a structure in which ultra-fine nitride precipitated particles are grown and stabilized with keeping the worked structure of the worked piece.Type: GrantFiled: November 21, 2001Date of Patent: July 8, 2003Assignee: Japan Science and Technology CorporationInventors: Jun Takada, Masahiro Nagae, Yutaka Hiraoka, Yoshito Takemoto
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Patent number: 6554914Abstract: The present invention pertains to systems and methods for passivating the copper seed layer deposited in Damascene integrated circuit manufacturing. More specifically, the invention pertains to systems and methods for depositing the copper seed layer by physical vapor deposition, while passivating the copper during or immediately after the deposition in order to prevent excessive oxidation of the copper. The invention is applicable to dual Damascene processing.Type: GrantFiled: February 2, 2001Date of Patent: April 29, 2003Assignee: Novellus Systems, Inc.Inventors: Robert T. Rozbicki, Ronald Allan Powell, Erich Klawuhn, Michal Danek, Karl B. Levy, Jonathan David Reid, Mukul Khosla, Eliot K. Broadbent
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Patent number: 6530998Abstract: A ceramic hard layer is formed on the surface of a formed article by subjecting the formed article of a substantially amorphous alloy to a heat treatment in an atmosphere containing a reactive gas under the conditions of temperature and time falling within the amorphous region in the isothermal transformation curve (TTT curve) of the alloy. The heat treatment is carried out, for instance, in an atmosphere containing oxygen and/or nitrogen at a concentration of not less than 1 ppm or in the air at a temperature of not less than the lowest temperature required for the oxidation or nitriding reaction of at least one component element of the matrix material. By this heat treatment, it is possible to produce a ceramic hard layer on the surface of the article in such a manner that the content of oxide and/or nitride gradually decreases in the depth direction.Type: GrantFiled: November 1, 2000Date of Patent: March 11, 2003Assignee: YKK CorporationInventor: Hitoshi Oofune
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Patent number: 6524401Abstract: While a nitride film is formed on a substrate containing metallic aluminum, a fluctuation in forming nitride film can be prevented, or the formation of the nitride film can be accelerated. A substrate containing at least metallic aluminum is subjected to a heating treatment in vacuum of 10−3 torr or less, and subsequently it is subjected to a heating/nitriding treatment in a atmosphere containing at least nitrogen to form a nitride film. A porous body through which a nitrogen atoms containing gas flow is clarified by heating at a temperature of 1000° C. or more under pressure of 10−4 torr or less, and then the porous body is contacted the atmosphere during the heating/nitriding step.Type: GrantFiled: July 30, 2001Date of Patent: February 25, 2003Assignee: NGK Insulators, Ltd.Inventors: Morimichi Watanabe, Shinji Kawasaki, Takahiro Ishikawa
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Patent number: 6451129Abstract: A decorative titanium material according to the present invention eliminates a deterioration of the appearance even after processing, that is, provides a small surface roughness, and has a hardened layer of titanium at the surface of the titanium material, this hardened surface layer including nitrogen and oxygen, and having a surface crystal grain size in the range from 0.1 to 60 &mgr;m.Type: GrantFiled: January 19, 1999Date of Patent: September 17, 2002Assignee: Citizen Watch Co., Ltd.Inventors: Masahiro Sato, Yoshitugu Sibuya, Junji Sato
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Patent number: 6364965Abstract: A method for producing an aluminum-containing member, comprising the steps of heating a substrate containing at least metallic aluminum in vacuum of not more than 10−3 torrs, and continuing with the heating step, forming a nitride in a surface portion of the substrate by heating/nitriding the substrate in a nitrogen atmosphere continuously to the above heating step.Type: GrantFiled: February 4, 2000Date of Patent: April 2, 2002Assignee: NGK Insulators, Ltd.Inventors: Masaaki Masuda, Taketoshi Tsutsumi, Yuji Katsuda
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Publication number: 20020009551Abstract: A method for nitriding a metallic base material at low temperatures in a salt bath containing electrolyzed titanium metal. A nitride coating of exceptional depth and hardness is obtained in a very short operating time due to the rapid nitriding process. The method is applicable to steel, titanium, aluminum and alloys thereof.Type: ApplicationFiled: June 1, 1999Publication date: January 24, 2002Inventor: JONG HO KO
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Publication number: 20010053460Abstract: A decorative titanium material according to the present invention eliminates a deterioration of the appearance even after processing, that is, provides a small surface roughness, and has a hardened layer of titanium at the surface of the titanium material, this hardened surface layer including nitrogen and oxygen, and having a surface crystal grain size in the range from 0.1 to 60 &mgr;m.Type: ApplicationFiled: January 19, 1999Publication date: December 20, 2001Inventors: MASAHIRO SATO, YOSHITUGU SIBUYA, JUNJI SATO
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Patent number: 6328819Abstract: A method is provided for heat treatment of metal workpieces obtain a substantially uniform nitride layer, even in workpieces comprising high alloy iron articles. The following method steps are provided: a) heating the workpieces to a temperature between 400° C. and 500° C. in a gas atmosphere comprising only ammonia; b) continuing to heat the workpieces to a temperature between 500° C. and 700° C. in a gas atmosphere containing ammonia and an added oxidizing agent; c) maintaining the workpieces at this temperature and in this gas atmosphere for a period of between 0.1 hour and 5 hours; d) continuing to maintain the workpieces at this temperature for a period of between 1 hour and 100 hours in a gas atmosphere containing ammonia or containing ammonia and a carbon-releasing substance; and, e) cooling the workpieces to room temperature.Type: GrantFiled: April 28, 2000Date of Patent: December 11, 2001Assignee: Ipsen International GmbHInventors: Wolfgang Lerche, Bernd Edenhofer, Michael Lohrmann
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Patent number: 6221173Abstract: Disposing the titanium or titanium alloy in a vacuum vessel, and applying annealing treatment thereto by heating (a heating process); feeding a mixed gas consisting primarily of nitrogen with a trace of oxygen component into the vessel, and heating inside the vacuum vessel at temperatures in the range of 700 to 800° C. in a predetermined reduced pressure condition for a predetermined length of time such that nitrogen and oxygen are diffused into the interior of the titanium or titanium alloy from the surface thereof so as to pass into solid solution therein (a hardening treatment process); and cooling the titanium or titanium alloy to room temperature after the hardening treatment process (a cooling process), are carried out. After completion of the processes described above, a hard surface layer 101 is formed in the surface region of the titanium or titanium alloy 100.Type: GrantFiled: September 24, 1998Date of Patent: April 24, 2001Assignee: Citizen Watch Co., Ltd.Inventors: Yoshitsugu Shibuya, Masahiro Sato, Junji Sato, Takanori Nanya, Kenji Hanai
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Patent number: 6168694Abstract: Metal nitride, carbonitride, and oxycarbonitride powder with high surface area (up to 150 m2/g) is prepared by using sol-gel process. The metal organic precursor, alkoxides or amides, is synthesized firstly. The metal organic precursor is modified by using unhydrolyzable organic ligands or templates. A wet gel is formed then by hydrolysis and condensation process. The solvent in the wet gel is then be removed supercritically to form porous amorphous hydroxide. This porous hydroxide materials is sintered to 725° C. under the ammonia flow and porous nitride powder is formed. The other way to obtain high surface area nitride, carbonitride, and oxycarbonitride powder is to pyrolyze polymerized templated metal amides aerogel in an inert atmosphere. The electrochemical capacitors are prepared by using sol-gel prepared nitride, carbonitride, and oxycarbonitride powder. Two methods are used to assemble the capacitors.Type: GrantFiled: February 4, 1999Date of Patent: January 2, 2001Assignee: Chemat Technology, Inc.Inventors: Yuhong Huang, Oiang Wei, Chung-tse Chu, Haixing Zheng
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Patent number: 6129988Abstract: The present invention generally describes methods for modifying MCrAlY coatings by using gaseous carburization, gaseous nitriding or gaseous carbonitriding. The modified MCrAlY coatings are useful in thermal barrier coating systems, which may be used in gas turbine engines.Type: GrantFiled: August 14, 1998Date of Patent: October 10, 2000Assignee: Siemens Westinghouse Power CorporationInventors: Steven J. Vance, John G. Goedjen, Stephen M. Sabol, Kelly M. Sloan
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Patent number: 6117249Abstract: A method of treating a metallic machine part to increase wear life and to change surface appearance comprising the steps of roughening the surface, thereafter changing its color by case hardening and, subsequently, increasing the lubricity of the case hardened surface by coating the surface with a pigmented, solid perfluorinated lubricant of a color comparable to the color of the case hardened surface.Type: GrantFiled: February 13, 1998Date of Patent: September 12, 2000Assignee: Kerk Motion Products, Inc.Inventors: Keith W. Erikson, Kenneth W. Erikson
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Patent number: 6090223Abstract: By forming a Cr playing layer on the surface of a metal and forming a CrN film by nitriding the surface thereof, it is possible to improve the surface hardness, wear resistance, corrosion resistance, etc., of the metal; wherein the nitriding treatment of the Cr plating layer surface is carried out by a method of heating in a nitrided atmosphere, preferably heated in a nitrided atmosphere which includes an ammonia decomposed gas treated in advance with an ammonia decomposition catalyst as a nitrogen source; in addition it is preferable that before the nitriding treatment, the Cr plating layer surface is purified and activated by heating in a halogen compound or a reacting gas which includes halogen.Type: GrantFiled: June 25, 1998Date of Patent: July 18, 2000Assignee: Showa Denko K.K.Inventors: Masayuki Kiuchi, Makoto Funai
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Patent number: 6086684Abstract: A surface treating is performed by an electric discharge. The electric discharge is generated by applying a voltage between an electrode and a metal workpiece. The electrode is a solid or green compact electrode or the like which is made of a reforming material. The workpiece may be an end mill or the like. Then, a coating layer is formed on a surface of the metal workpiece. Thereafter, a nitriding treatment is performed on the coating layer in a nitriding vessel or the like. Thus, a hard coating layer of better quality is formed on the surface of the workpiece whether a material of the workpiece is steel or hard metal.Type: GrantFiled: June 2, 1998Date of Patent: July 11, 2000Assignees: Japan Science and Technology Corporation, Nagao Saito, Naotake Mohri, Mitsubishi Denki Kabushiki KaishaInventors: Nagao Saito, Naotake Mohri, Yoshiki Tsunekawa, Kohei Shimamoto, Akihiro Goto, Takuji Magara, Yoshihito Imai, Hidetaka Miyake
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Patent number: 6074494Abstract: This invention aims to provide a nitriding method of forming a relatively thick nitride layer on the surface of an aluminum material containing silicon, and an auxiliary agent for nitriding. By using a nitriding auxiliary agent mainly comprising aluminum containing a metal such as lithium or boron, which has a high bonding strength with oxygen, coexists with silicon to form substantially no silicide, or a nitriding auxiliary agent mainly comprising an Al--Mg--Cu alloy or an Mg--Zn--Cu alloy, heat treatment is applied by nitrogen gas with the aluminum material to be nitrided contacted with the nitriding auxiliary agent. Hence, a thick nitride layer can be easily formed even on the surface of an aluminum material containing silicon, and this is most suitable to surface nitride aluminum-silicon alloys, which possess superior castability.Type: GrantFiled: June 2, 1997Date of Patent: June 13, 2000Assignees: Toyota Jidosha Kabushiki Kaisha, Toyo Aluminium Kabushiki KaishaInventors: Hirohisa Miura, Yasuhiro Yamada, Haruzo Katoh
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Patent number: 6020025Abstract: A crank shaft is constructed only at the surface layer of a journal portion with a hard nitride layer, so that the resultant crank shaft is available at a low cost, not so heavy and excellent in durability in comparison with a case employing a hard material for the whole crank shaft. Also, a method of manufacturing a crank shaft according to the present invention employs fluorinating process prior to nitriding process to change a passive coat layer, such as oxide layer on the surface of the journal portion to a fluoride layer, which protects the same surface. Therefore, even when there is space of time between formation of fluoride on the surface of the journal portion and nitriding process, the fluoride layer protects and keeps the surface of the journal portion in a favorable condition, resulting in that re-formation of oxide layer on that surface is prevented.Type: GrantFiled: April 17, 1995Date of Patent: February 1, 2000Assignee: Daidousanso Co., Ltd.Inventor: Akira Yoshino
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Patent number: 5916383Abstract: A method for shot peening a hard metal product that has a hardened surface. The method includes projecting shot on the hardened surface of the hard metal product. The ratio of the Vickers hardness of the shot to that of the hardened surface is 0.8-1.6, and the diameter of the shot is 30-250.mu..Type: GrantFiled: July 11, 1997Date of Patent: June 29, 1999Assignee: Sintokogio, Ltd.Inventors: Hitoshi Rokutanda, Toru Takahashi, Junkou Kurosaki, Toshiroh Ito
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Patent number: 5912399Abstract: A new tungsten compound is formed by reacting ammonium metatungstate with guanidine carbonate. Such a compound can be converted to metallic tungsten, tungsten carbide or oxycarbide, and tungsten nitride or oxynitride. One can also make multiphase composite particles based on molybdenum, tungsten or their compounds (such as carbide or nitride), and at least one other metallic phase, such as cobalt, copper, nickel, iron or silver. The process involves first dispersing particles of a refractory metal or its compounds in a liquid medium, followed by inducing a chemical reaction in the liquid phase to generate a new solid phase which coats or mixes with the dispersed particles. The solid phase includes elements required in the final composite. After removing the liquid phase, the remaining solid is converted by hydrogen reduction into the final products.Type: GrantFiled: November 14, 1996Date of Patent: June 15, 1999Assignee: Materials Modification Inc.Inventors: Chunzhe C. Yu, Reshma Kumar
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Patent number: 5888269Abstract: A case nitrided aluminum product is produced by contacting an aluminum product with a nitriding agent at a part of a surface thereof at least, and by nitriding the aluminum product at the surface with an ambient gas at a temperature of a melting point of the aluminum product or less while keeping the aforementioned contact. The nitriding agent includes an aluminum powder, and the ambient gas virtually includes a nitrogen gas. The resulting nitriding layer has a depth of 5 micrometers or more, and it exhibits a case hardness of from 250 to 1,200 mHv. Thus, it is possible to form the deep and hard nitriding layer on the aluminum product with ease under the conditions where it has been said to be too difficult to nitride aluminum products. The case nitrided aluminum product can appropriately make sliding parts which require high wear resistance.Type: GrantFiled: March 17, 1997Date of Patent: March 30, 1999Assignees: Toyota Jidosha Kabushiki Kaisha, Toyo Aluminium Kabushiki KaishaInventors: Yasuhiro Yamada, Hirohisa Miura, Mamoru Okamoto, Takashi Matsufuji, Taro Tatsumi, Kazuo Fujii
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Patent number: 5865908Abstract: A composite diffusion type nitriding method and a composite diffusion type nitriding apparatus of the present invention are effectively used for nitriding various materials, such as machine parts, as well as a material which is difficult for nitriding by a conventional method. The composite diffusion nitriding apparatus is formed of a container filled with solid granular materials, a furnace for housing the container therein, a nitriding gas introduction path for introducing the nitriding gas into the container, and an exhausting path for exhausting the gas from the container. In the method, the material to be nitrided is placed in the solid granular materials, and the nitriding gas is supplied to flow through the solid granular materials to thereby nitride the material.Type: GrantFiled: January 27, 1997Date of Patent: February 2, 1999Assignees: Shimadzu Mekutemu Kabushiki Kaisya, Lihit Seiko Co., Ltd.Inventors: Masami Takei, Hideto Fujita, Ryoji Fujino
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Patent number: 5776264Abstract: Amorphous tungsten, cobalt, nickel, molybdenum, iron and alloys thereof can be formed by reducing metal-containing compositions to form the elemental metal wherein the particle size of the elemental metal is less than about 80 microns. This is oxidized in an oxygen-starved environment containing less than 3% oxygen and an inert gas to slowly oxidize the elemental metal. By oxidizing the metal under these conditions, the normal exotherm occurring during oxidation is avoided. The slow oxidation of the metal continues forming an amorphous metal oxide. The amorphous metal oxide can then be reacted in a reducing environment such as hydrogen to form the amorphous elemental metal. This amorphous elemental metal can then be reacted with a carburizing gas to form the carbide or ammonia gas to form the nitride or hexamethylsilane to form the silicide. This permits gas/solid reactions. The amorphous metal can also be used in a variety of different applications.Type: GrantFiled: April 12, 1996Date of Patent: July 7, 1998Assignee: Rutgers UniversityInventors: Larry E. McCandlish, Bernard Kear, Nicos C. Angastiniotis
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Patent number: 5645944Abstract: The invention relates to the application of molybdenum alloys, which are superficially hardened by means of nitriding, for female dies and comparable construction components for extruding light and nonferrous metals. It is possible through the application of these materials to achieve distinct improvements over the materials used heretofore with respect to the tool life, extrusion rate and surface quality of the extruded material.Type: GrantFiled: July 18, 1995Date of Patent: July 8, 1997Assignee: Schwarzkopf Technologies Corp.Inventors: Gerhard Dipl-Ing Leichtfried, Hans-Peter Martinz
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Patent number: 5599404Abstract: A substrate material to be coated with either a nitride, carbide, or oxide contains a small percent of a specific reactive element, like titanium, which forms very stable nitrides, carbides, or oxides. The material also contains larger percentages of elements, such as chromium, which form less-stable nitrides, carbides, or oxides. When the substrate material is immersed in a process medium which contains reactants, such as nitrogen, carbon, or oxygen, at a chosen elevated temperature and concentration, the less-stable nitrides, carbides, or oxides are reduced and cannot form a coating on the material surface. Thus, only a very stable nitride, carbide, or oxide can form a strong, adherent coating.Type: GrantFiled: April 25, 1995Date of Patent: February 4, 1997Inventor: Donald L. Alger
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Patent number: 5593511Abstract: Titanium films are nitrided at temperatures less than 650.degree. C., and preferably between 400.degree. C. and 500.degree. C., by treating the titanium film with a plasma formed from a nitriding gas at elevated temperatures. The plasma is created by subjecting the nitriding gas to RF energy, preferably an electrode having a frequency of 13.56 MHz or less. The reaction temperature can be reduced by lowering the plasma frequency to less than 500 KHz. This provides for nitridization at temperatures of 480.degree. C. and lower.Type: GrantFiled: December 6, 1995Date of Patent: January 14, 1997Assignees: Sony Corporation, Materials Research CorporationInventors: Robert F. Foster, Joseph T. Hillman
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Patent number: 5582655Abstract: A case nitrided aluminum product is produced by contacting an aluminum product with a nitriding agent at a part of a surface thereof at least, and by nitriding the aluminum product at the surface with an ambient gas at a temperature of a melting point of the aluminum product or less while keeping the aforementioned contact. The nitriding agent includes an aluminum powder, and the ambient gas virtually includes a nitrogen gas. The resulting nitriding layer has a depth of 5 micrometers or more, and it exhibits a case hardness of from 250 to 1,200 mHv. Thus, it is possible to form the deep and hard nitriding layer on the aluminum product with ease under the conditions where it has been said to be too difficult to nitride aluminum products. The case nitrided aluminum product can appropriately make sliding parts which require high wear resistance.Type: GrantFiled: June 6, 1995Date of Patent: December 10, 1996Assignees: Toyota Jidosha Kabushiki Kaisha, Toyo Aluminium Kabushiki KaishaInventors: Yasuhiro Yamada, Hirohisa Miura, Mamoru Okamoto, Takashi Matsufuji, Taro Tatsumi, Kazuo Fujii
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Patent number: 5580397Abstract: A carbide and carbonitride surface treatment method for refractory metals is provided, in steps including, heating a part formed of boron, chromium, hafnium, molybdenum, niobium, tantalum, titanium, tungsten or zirconium, or alloys thereof, in an evacuated chamber and then introducing reaction gases including nitrogen and hydrogen, either in elemental or water vapor form, which react with a source of elemental carbon to form carbon-containing gaseous reactants which then react with the metal part to form the desired surface layer. Apparatus for practicing the method is also provided, in the form of a carbide and carbonitride surface treatment system (10) including a reaction chamber (14), a source of elemental carbon (17), a heating subassembly (20) and a source of reaction gases (23).Type: GrantFiled: January 26, 1995Date of Patent: December 3, 1996Assignee: The United States of America as represented by the Department of EnergyInventors: Glenn A. Meyer, Marcus A. Schildbach
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Patent number: 5514225Abstract: A case nitrided aluminum product is produced by contacting an aluminum product with a nitriding agent at a part of a surface thereof at least, and by nitriding the aluminum product at the surface with an ambient gas at a temperature of a melting point of the aluminum product or less while keeping the aforementioned contact. The nitriding agent includes an aluminum powder, and the ambient gas virtually includes a nitrogen gas. The resulting nitriding layer has a depth of 5 micrometers or more, and it exhibits a case hardness of from 250 to 1,200 mHv. Thus, it is possible to form the deep and hard nitriding layer on the aluminum product with ease under the conditions where it has been said to be too difficult to nitride aluminum products. The case nitrided aluminum product can appropriately make sliding parts which require high wear resistance.Type: GrantFiled: October 4, 1994Date of Patent: May 7, 1996Assignees: Toyota Jidosha Kabushiki Kaisha, Toyo Aluminum K.K.Inventors: Yasuhiro Yamada, Hirohisa Miura, Mamoru Okamoto, Takashi Matsufuji, Taro Tatsumi, Kazuo Fujii
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Patent number: 5505791Abstract: The present invention relates to nickel alloy products with their surfaces nitrided and hardened which are formed by pressure casting nickel alloy material, and nitrided and hardened layers are formed in surface layers. Since the nitrided and hardened surfaces of the nickel alloy products according to the invention have much better corrosion resistance than iron products have, anticorrosion treatment such as plating is not required, and rich lubricity and excellent tightening property can be obtained without having seizure and scuffing phenomena.Type: GrantFiled: April 27, 1995Date of Patent: April 9, 1996Assignee: Daidousanso Co., Ltd.Inventors: Masaaki Tahara, Haruo Senbokuya, Kenzo Kitano, Tadashi Hayashida, Teruo Minato
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Patent number: 5443663Abstract: The present invention relates to ion nitriding of pure titanium or titanium-containing alloys at low pressure by intensifying the glow discharge. Plasma intensification was produced by thermionic emission in conjunction with a triode glow discharge system. Effective ion nitriding can be achieved by employing the present invention at relatively low temperatures (480.degree. C.) and with significantly enhanced compound layer growth kinetics compared to the conventional nitriding techniques. Processed Ti and Ti-6Al-4V developed a surface layer of TiN followed by a Ti.sub.2 N layer and an interstitial nitrogen diffusion zone. Processed specimens showed a three fold increase in surface hardness. Surface roughness was found to be a function of the degree of plasma intensification. Processing of Ti-6Al-4V resulted in a higher wear, corrosion and wear-corrosion resistance.Type: GrantFiled: April 29, 1994Date of Patent: August 22, 1995Assignee: Board of Supervisors of Louisiana State University and Agricultural and Mechanical CollegeInventor: Efstathius Meletis
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Patent number: 5427631Abstract: Objects of titanium or titanium alloys having the surface converted to a hard and wear-resistant nitride layer with good adhesion, which is distributed uniformly and also provides internal capillaries. The objects are produced by being treated in a vacuum furnace with an atmosphere of pure nitrogen gas at a temperature of 650.degree.-1000.degree. C. and at a pressure below atmospheric pressure. The thickness of the nitride layer can be controlled by controlling the treatment time and temperature.Type: GrantFiled: March 30, 1994Date of Patent: June 27, 1995Assignee: Ytbolaget I Uppsala AktiebolagInventors: Erik Johansson, Helena Westberg
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Patent number: 5419787Abstract: An insulating film with low thermal expansion characteristics is formed by depositing aluminum alloy materials in thin film form without the use of high temperatures and which can then be oxidized to create an insulating film which has low stress. A mixture of aluminum and magnesium oxides, known as spinel, has the proportions which are approximately correct for zero expansion when crystallization results from the oxidation.Type: GrantFiled: June 24, 1994Date of Patent: May 30, 1995Assignee: The United States of America as represented by the Secretary of the Air ForceInventor: Mark W. Levi
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Patent number: 5415704Abstract: This invention provides surface hardened, abrasion resistant high strength, biocompatible metal medical implants, in particular, titanium alloy implants which do not include any elements which have been shown or suggested as having short term or long term potential adverse effect from a standpoint of biocompatibility. Further, the invention provides methods of strengthening and hardening the surfaces of other titanium, zirconium, and cobalt-based alloy implants with small concentrations of a metal solute such as zirconium, yttrium, tantalum, aluminum, silicon, chromium, or thorium via internal oxidation or nitridation. Alternatively, nitrogen, oxygen, or carbon can be diffused directly into the surface of the implants by interstitial hardening to further increase the surface abrasion resistance of these internally oxidized or internally nitridized implant metal or metal alloys.Type: GrantFiled: September 13, 1993Date of Patent: May 16, 1995Assignee: Smith & Nephew Richards Inc.Inventor: James A. Davidson
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Patent number: 5399207Abstract: A process and apparatus for forming a hardened outer shell (40) on a refractory metal workpiece (36) preferably heated in a fluidized bed of metallic oxide particles (38) in an environment of an inert gas and a reactive gas with the reactive gas either oxygen or nitrogen. The workpieces (36) are heated in the fluidized bed to a temperature between 800.degree. F. and 1600.degree. F. for a period of over two hours to form hardened outer shell (40) in two layers (42, 44). Outer layer (42) is an oxide or nitride layer having a thickness (T1) between 10 microns and 25 microns. Inner layer (44) is a case hardened layer of the refractory metal having a thickness (T2) between 25 microns and 75 microns. In one embodiment (FIG. 3 ) workpieces (56) may be cold worked by peening from finely divided metal oxide particles (54) to provide a uniform surface texture for subsequent hardening.Type: GrantFiled: November 29, 1993Date of Patent: March 21, 1995Assignee: Fike CorporationInventor: Willard E. Kemp
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Patent number: 5372655Abstract: Method for the treatment of alloy steels and refractory metals such as Ti, Zr and Nb, especially for depassivation and subsequent thermochemical surface treatment in a process chamber (1, 2) under the action of pressure and temperature, wherein, in a first process step, a first gas or gas mixture from the group N.sub.2, H.sub.2 or NH.sub.3 is admitted for the depassivation into a process chamber (1), a pressure greater than 1 bar a and a temperature between 100.degree. C. and 1,000.degree. C. is established in the chamber (1), and in a second process step a second gas or gas mixture from the group of N-, C- or B-containing gases is admitted into a process chamber (1, 2) for the thermochemical surface treatment, and a temperature between 100.degree. C. and 1,000.degree. C. at a pressure greater than or equal to 1 bar a is established.Type: GrantFiled: April 14, 1992Date of Patent: December 13, 1994Assignee: Leybold Durferrit GmbHInventors: Friedrich Preisser, Peter Minarski, Albrecht Melber, Klaus Zimmerman
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Patent number: 5338374Abstract: A process for forming a copper alloy which is strengthened while maintaining good electrical and thermal conductivity by the addition of TiN or ZrN consists of external nitridation of a mechanically alloyed powder mixture followed by further mechanical alloying to break down the surface coating which forms during nitridation.Type: GrantFiled: July 26, 1993Date of Patent: August 16, 1994Assignee: The United States of America as represented by the Secretary of the NavyInventors: Harris L. Marcus, Zwy Eliezer, Morris E. Fine
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Patent number: 5322676Abstract: A process for producing low-cost furnace atmospheres suitable for annealing and heat treating ferrous and nonferrous metals and alloys, brazing metals and ceramics, sealing glass to metal, and sintering metal and ceramic powders in a continuous furnace equipped with an ammonia dissociator from non-cryogenically produced nitrogen containing from 0.05 to 5.0% residual oxygen is presented. The disclosed process involves mixing non-cryogenically produced nitrogen with a pre-determined amount of a reducing gas such as hydrogen, ammonia, a C, H, and O containing hydrocarbon such as an alcohol, an ether, etc., or a mixture thereof, passing the mixture through an ammonia dissociator and converting the residual oxygen to an acceptable form such as moisture, carbon monoxide, carbon dioxide, or mixture thereof, and using the resultant gaseous mixture for annealing and heat treating ferrous and nonferrous metals and alloys, brazing metals and ceramics, sealing glass to metal, and sintering metal and ceramic powders.Type: GrantFiled: December 22, 1992Date of Patent: June 21, 1994Assignee: Air Products and Chemicals, Inc.Inventor: Michael J. Epting
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Patent number: 5320689Abstract: There is provided a composite copper alloy having a copper alloy core and a modified surface layer containing a nitride or carbide film. Alternatively, the modified surface layer may contain a carbo-nitride film. The alloy is formed by reacting a copper alloy with nitrogen, carbon or a nitrogen/carbon mixture at elevated temperatures. The resultant surface layer improves the tribological and mechanical properties of the alloy while maintaining useful electrical conductivity.Type: GrantFiled: March 1, 1993Date of Patent: June 14, 1994Assignee: Olin CorporationInventors: Deepak Mahulikar, Brian Mravic
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Patent number: 5320686Abstract: Objects of titanium or titanium alloys having the surface converted to a hard and wear-resistant nitride layer with good adhesion, which is distributed uniformly and also provides internal capillaries. The objects are produced by being treated in a vacuum furnace with an atmosphere of pure nitrogen gas at a temperature of 650.degree.-1000.degree. C. and at a pressure below atmospheric pressure. The thickness of the nitride layer can be controlled by controlling the treatment time and temperature.Type: GrantFiled: March 21, 1991Date of Patent: June 14, 1994Assignee: Tisurf International ABInventors: Erik Johansson, Helena Westberg