Patents by Inventor Gunter Petzow
Gunter Petzow 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).
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Patent number: 5250509Abstract: The invention relates to an oxide-ceramic superconducting material which contains bismuth, strontium, calcium and copper, having an overall composition of Bi.sub.y Ca.sub.2 Sr.sub.2 Cu.sub.3 O.sub.x, where y is an integer from 2.35 to 2.6 and x is about 10 to 12. The material has a critical temperature T above 105 K and has a proportion of the phase Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.x of at least 85% by volume. The invention also relates to a process for producing a bismuth-containing superconducting material which comprises holding the oxides or oxide precursors of bismuth, strontium, calcium and copper at a temperature in the range from 850.degree. to 890.degree. C. over a time span of a plurality of hours and adhering to the following atomic ratios:Bi:Cu>2:3Ca:Sr=0.9 to 1.50.SIGMA.(Sr+Ca):Cu=4.2:3 to 4:3.33Bi:.SIGMA.(Sr+Ca)=2.35:4 to 3.Type: GrantFiled: February 20, 1992Date of Patent: October 5, 1993Assignee: Hoechst AktiengesellschaftInventors: Bernhard Hettich, Peter Majewski, Klaus Schulze, deceased, Gunter Petzow
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Patent number: 5194099Abstract: A sinter magnet based on Fe-Nd-B with improved coercive field strength and reduced temperature dependency thereof consists of 25 to 50 wt. % Nd, 0.5 to 2 wt. % B, 0 to 5 wt. % Al, 0.5 to 3 wt. % O, remainder Fe and usual impurities and has an oxygen content which is adjusted by the addition of oxygen or of oxygen-containing compounds, especially of an Al and/or Nd oxide, before the dense sintering. It is obtainable by the melting together of the pure components with formation of a pre-alloy, pulverisation of the pre-alloy, alignment of the powder in a magnetic field and pressing to a green formed body, sintering at 1040.degree. to 1100.degree. C. and subsequent annealing at 600.degree. to 700.degree. C., whereby one adds the oxygen as Al or Nd oxide or via the grinding and/or sintering atmosphere.Type: GrantFiled: May 23, 1990Date of Patent: March 16, 1993Assignees: 501 Max-Planck-Gesellschaft zur Forderung der Wissenschaften E.V., 502 Robert Bosch GmbHInventors: Friedrich Esper, Waldemar Draxler, Gunter Petzow, Andreas Buchel, Klaus-Dieter Durst, Ernst-Theo Henig, Gerhard Schneider, Helmut Kronmuller
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Patent number: 5162272Abstract: The invention relates to a novel sinterable ceramic powder, to its preparation and to its further processing to give a silicon nitride ceramic, and to this material itself and its use. The sinterable ceramic powder is produced by melting a polysilazane or dissolving it in an organic solvent, suspending a powdered sinter aid in this melt or solution, then pyrolyzing the melt, or the residue obtained after evaporation of the solvent, at 500.degree. to 1600.degree. C. in a protective gas atmosphere, the polysilazane eitherA) being obtainable by reacting at least one of the oligosilazanes of the formula (I) ##STR1## in which a, b, c and d are the mole fractions of the respective structural units and where 0.ltoreq.a.ltoreq.1, 0.ltoreq.b.ltoreq.1, 0.ltoreq.c.ltoreq.0.7, 0.ltoreq.d.ltoreq.0.7, 0.3.ltoreq.a+b, c+d.ltoreq.0.7 and n is approximately 2 to approximately 12, with at least one of the chlorosilanes R.sup.6 R.sup.7 SiCl.sub.2, R.sup.8 SiCl.sub.3, Cl.sub.2 R.sup.9 Si--CH.sub.2 CH.sub.2 --SiR.sup.9 Cl.sub.Type: GrantFiled: March 23, 1990Date of Patent: November 10, 1992Assignee: Hoechst AktiengesellschaftInventors: Marcellus Peuckert, Tilo Vaahs, Martin Bruck, Hans-Jerg Kleiner, Ralf Riedel, Martin Sehr, Gunter Petzow
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Patent number: 5106793Abstract: Carbide fiber- and carbide whisker-strengthened silicon nitride bodies are hot-isostatic pressed without encapsulation of the pressureless pre-sintered formed body at temperature between 1000.degree. and 3000.degree. C. in a nitrogen-protective gas atmosphere. At a low nitrogen partial pressure but high total gas pressure, a maximum consolidation can be achieved already at relatively low temperatures without destruction of the carbide fibers or carbide whiskers.Type: GrantFiled: September 11, 1989Date of Patent: April 21, 1992Assignee: Max-Planck-Gesellschaft zur Foederung der Wissenschaften e.V.Inventors: Peter Greil, Klaus Nickel, Michael Hoffmann, Gunter Petzow
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Patent number: 5039632Abstract: The present invention relates to an SiC powder suitable for the production of SiC sintered ceramics with compounds applied to its surface, these compounds being boron nitride and carbon; processes for production of the SiC powders; and the use of these powders to produce SiC sintered mouldings.Type: GrantFiled: October 4, 1989Date of Patent: August 13, 1991Assignee: Bayer AGInventors: Ralf Riedel, Gerd Passing, Gunter Petzow, Wolfgang Krumbe, Gerhard Franz
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Patent number: 4908171Abstract: A novel method of sintering Si.sub.3 N.sub.4 shaped bodies which method comprises grinding Si.sub.3 N.sub.4 with the use of a grinding material down to a surface area magnitude of 10.5 to 35 m.sup.2 /g and an average particle size from 0.2 to 0.005 .mu.m, shaping the powder obtained, and sintering the compact under inert gas or nitrogen at a temperature from 1700.degree. to 1900.degree. C.Type: GrantFiled: January 27, 1988Date of Patent: March 13, 1990Assignee: Max-Planck-Gesellschaft zur Foedering der Wissenschaften e.V.Inventors: Nils Claussen, Jurgen Jahn, Gunter Petzow
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Patent number: 4904623Abstract: Boron carbide/transition metal boride molded articles produced by hot preng a mixture of from 25 to 75% by weight of boron carbide, from 14 to 40% by weight or boron, from 10 to 50% by weight of tungsten and/or titanium carbide, from 0 to 6% by weight of cobalt and from 0 to 8% by weight of silicon to convert the carbide into the corresponding boride.Type: GrantFiled: August 2, 1988Date of Patent: February 27, 1990Assignee: Max-Planck-Gesellschaft zur Forderung der Wissenschaften e.V.Inventors: Gunter Petzow, Heinrich Hofmann, Kurt Weiss
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Patent number: 4900492Abstract: The present invention provides a fine-grained ceramic formed body of 0.5 to mole % rare earth oxide and 0.5 to 7 mole % MgO-containing ZrO.sub.2, wherein the cubic granules thereof are coated with Mg-Al spinel particles.The present invention also provides a process for the production of such formed bodies, wherein a ZrO.sub.2 powder alloyed with rare earth oxide, which contains small amounts of Al.sub.2 O.sub.3, is pressed and sintered in the presence of MgO at a temperature of from 1400.degree. to 1600.degree. C. and optionally subsequently tempered at a temperature of from 1200.degree. to 1350.degree. C.Type: GrantFiled: February 9, 1988Date of Patent: February 13, 1990Assignee: Max-Planck-Gesellschaft zur Foerderung der Wissenschaften e.V.Inventors: Nils Claussen, Helmut Schubert, Manfred Ruhle, Gunter Petzow
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Patent number: 4855259Abstract: Ceramic moldings containing finely crystalline cordierite are described, which are obtainable by the intensive grinding of precrystallized cordierite powder, mixing the powder with second additive phases of higher modulus of elasticity, shaping the mixture, and sintering the greenware thus obtained in a siliceous atmosphere at temperatures between 900.degree. and 1400.degree. C. The moldings according to the invention have not only good mechanical strengths but also outstanding dielectric and thermal properties; they are therefore especially suitable for use as dielectrics and as thermal insulating components.Type: GrantFiled: September 13, 1985Date of Patent: August 8, 1989Assignee: Firma Schott GlaswerkeInventors: Nils Claussen, Gunter Petzow, Houssmann, Wolfgang Panhorst, Karl-Ludwig Weisskopf
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Patent number: 4767727Abstract: The present invention provides a fibre-strengthened ceramic formed body with improved mechanical strength, wherein it contains at least 15% by volume of zirconium dioxide, hafnium dioxide or zirconium dioxide/hafnium dioxide composition in the form of monoclinic crystals and an amount of inorganic fibres sufficient for increasing the strength, which is obtainable by hot pressing a mixture of ceramic matrix materials, at least 15% by volume of tetragonal zirconium dioxide, hafnium dioxide or zirconium dioxide/hafnium dioxide composition particles and the fibres at a temperature above the tetragonal.fwdarw.monoclinic transition temperature.The present invention also provides a process for the production of such a ceramic formed body.Type: GrantFiled: May 23, 1986Date of Patent: August 30, 1988Assignee: Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften E.V.Inventors: Nils Claussen, Gunter Petzow
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Patent number: 4670408Abstract: A process for the preparation of boron carbide/transition metal boride mod articles comprising hot pressing a mixture of from 25 to 75% by weight of boron carbide, from 15 to 40% by weight of boron, from 0 to 8% by weight of silicon, from 10 to 50% by weight of tungsten and/or titanium carbide, and from 0 to 6% by weight of cobalt.Type: GrantFiled: September 18, 1985Date of Patent: June 2, 1987Assignee: Max-Planck-Gesellschaft Zur Foerderung der Wissenschaften E.V.Inventors: Gunter Petzow, Heinrich Hofmann, Kurt Weiss
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Patent number: 4525464Abstract: A ceramic body of zirconium dioxide containing, if desired, aluminum oxide, and partially stabilized with yttrium oxide and/or one or more rare earth oxides (e.g., cerium dioxide) and/or magnesium oxide and/or calcium oxide is partially stabilized with 0.5 to 5 mole-% of yttrium oxide and/or 5 to 12 mole-% of magnesium oxide and/or calcium oxide and/or cerium dioxide or one or more rare earth oxides, is 30 to 100% in the tetragonal lattice modification and has in the surface region a content of yttrium oxide, cerium dioxide, magnesium oxide, calcium oxide or rare earth oxide that is 1 to 20 mole-% higher than the average content, such that the body is coated with a thin, PSZ-like layer in a more highly stabilized tetragonal or with a layer that is predominantly in the cubic lattice form.Type: GrantFiled: June 12, 1984Date of Patent: June 25, 1985Assignee: Max-Planck-Gesellschaft zur Forderung der WissenschaftenInventors: Nils Claussen, Manfred Ruhle, Gunter Petzow
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Patent number: 4506024Abstract: The present invention is concerned with a ceramic formed body comprising a ceramic matrix and at least one phase of ceramic incorporation material dispersed therein, characterized by a dense, microcrack-free ceramic base matrix and compressive zones incorporated therein which consist of a mixture of the base matrix material with unstabilized zirconium dioxide particles which are predominantly monoclinic at ambient temperature.The present invention is also concerned with a process for the production of such ceramic formed bodies and with the use thereof as constructional elements in the hot region of heat engines.Type: GrantFiled: September 1, 1983Date of Patent: March 19, 1985Assignee: Max-Planck-Institut zur Foerderung der Wissenschaften e.V.Inventors: Nils Claussen, Gunter Petzow
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Patent number: 4421861Abstract: A ceramic formed body having high temperature change resistance and stren and being composed of a ceramic matrix with dispersed particles of ZrO.sub.2, HfO.sub.2, or mixture thereof, is formed of a powdered ceramic material which is a precursor to the matrix material of the ceramic matrix, mixed with a compound which can form ZrO.sub.2, HfO.sub.2 or mixture thereof upon reaction with the ceramic material, and thereafter densely sintered below the reaction temperature. The sintered body is then heat treated above the reaction temperature to convert the precursor ceramic material into the matrix material and form the ceramic body with in situ formation of the dispersed particles.Type: GrantFiled: May 19, 1980Date of Patent: December 20, 1983Assignee: Max-Planck-Gesellschaft zur Forderung der Wissenschaften e.v.Inventors: Nils Claussen, Gunter Petzow, Richard J. Brook
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Patent number: 4401729Abstract: A high-strength ceramic laminated tube comprising an inner tube of ceramic material and at least one outer tube of a metal or ceramic material shrunken onto the inner tube is provided, e.g., a ceramic tube capable of withstanding the mechanical stresses which occur in, e.g., a gun barrel, or in a bearing subjected to great stress.Type: GrantFiled: January 25, 1979Date of Patent: August 30, 1983Inventors: Nils Claussen, Gunter Petzow
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Patent number: 4322249Abstract: In a process for the production of dispersion ceramics by sintering or hot pressing of a mixture of a matrix-forming ceramic material and of at least one ceramic embedment material dispersible therein which at the sintering temperature of the ceramic and at room temperature is present in different enantiotropic solid modifications of different densities, a ceramic embedment material is employed which is divided into at least two groups of different, substantially uniform particle sizes, each group having different lower phase-transition temperatures.Type: GrantFiled: July 14, 1980Date of Patent: March 30, 1982Assignee: Max Planck GesellschaftInventors: Nils Claussen, Jurgen Jahn, Gunter Petzow
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Patent number: RE32449Abstract: A ceramic body of zirconium dioxide containing, if desired, aluminum oxide, nd partially stabilized with yttrium oxide and/or one or more rare earth oxides (e.g., cerium dioxide) and/or magnesium oxide and/or calcium oxide is partially stabilized with 0.5 to 5 mole-% of yttrium oxide and/or 5 to 12 mole-% of magnesium oxide and/or calcium oxide and/or cerium dioxide or one or more rare earth oxides, is 30 to 100% in the tetragonal lattice modification and has in the surface region a content of yttrium oxide, cerium dioxide, magnesium oxide, calcium oxide or rare earth oxide that is 1 to 20 mole-% higher than the average content, such that the body is coated with a thin, PSZ-like layer in a more highly stabilized tetragonal or with a layer that is predominantly in the cubic lattice form.Type: GrantFiled: January 23, 1986Date of Patent: June 30, 1987Assignee: Max-Planck-Gesellschaft zur Forderung der Wissenschaften e.VInventors: Nils Claussen, Manfred Ruhle, Gunter Petzow