Abstract: A method of manufacturing a shaped article from a powdered precursor, wherein the components of the powdered precursor are subjected to a self-propagating high-temperature synthesis (SHS) reaction and are consolidated essentially simultaneously. The shaped article requires essentially no machining after manufacture.
Type:
Grant
Filed:
September 3, 1993
Date of Patent:
January 17, 1995
Assignee:
Inland Steel Company
Inventors:
Kenneth F. Lowrance, II, Eric C. Knorr, William M. Goldberger, Daniel Boss, Doreen Edwards
Abstract: A thixoformable material and a method for forming it are provided in which the material comprises a series of sequentially deposited layers of substantially metallic material, at least some of the layers having different properties. The layers may be of different materials or the layers may differ in that some are provided with reinforcing material whereas other are not. The reinforcing material may consist of particles of spherical, fiberous or other shapes and may be made of various carbides or other suitable reinforcing materials.The thixoformable material may be formed in sheets, cylindrical forms or any other shape and subsequently cut to the volume and/or shape required for the forming stage.A layered material of this sort offers the advantages of thixoformable materials but with enhanced toughness and damage resistance due to the layered 3-dimensional structure.
Abstract: A method of making a composite orifice having a tungsten core which is diffusion bonded to a molybdenum shell. Tungsten and molybdenum powders in contact with each other in a mold are isostatically pressed to form a pressed bonded composite part. The pressed, unsintered tungsten core portion of the part is then machined to the desired dimensions. The pressed composite part is then sintered to form a diffusion bonded composite orifice. The pressed and sintered molybdenum shell portion of the orifice may then be machined to the desired dimensions.
Abstract: A process is proposed which serves to produce layer systems for gas sensors, the electrodes essentially being composed of a finely divided ceramic material and finely divided electron-conducting material. The process comprises adding stabilizer oxides to the electrode material in proportions above those necessary for full stabilization. As a result, a layer system having outstanding mechanical properties and high electrode load carrying capacity is obtained by a simple manufacturing process.
Abstract: A high temperature heat-treating jig characterized by forming a tungsten layer or a tungsten alloy layer on the surface of a heat-resistant base to avoid discoloration and color shading during the heat treatment at a high temperature.
Abstract: This invention relates to a diamond-coated hard material and a process for the production of the same. The feature of the diamond-coated hard material consists in that in a diamond-coated hard material comprising a substrate of a tungsten carbide-based cemented carbide having a diamond-coated layer provided on the surface of the substrate, a surface-modified layer containing no binder phase or containing a binder phase in a proportion of less than in the interior part of the substrate is present on the outermost surface of the substrate. This hard material can be produced by converting the substrate material into a sintered or heat treated surface or skin and then coating with diamond. The diamond-coated hard material of the present invention has such a high wear resistance and excellent bonding strength to the substrate that it can favorably be applied to various tools, parts, grinding wheels, etc.
Abstract: A heat sink composed of metal particles dispersed in a binder or a sintered structure in which the binder is removed; and the method of forming a heat sink by molding the heat sink from a thermoplastic or epoxy material which has been filled with metal particles.
Type:
Grant
Filed:
March 10, 1994
Date of Patent:
November 22, 1994
Assignee:
Iowa State University Research Foundation, Inc.
Inventors:
Robert L. Terpstra, Barbara K. Lograsso, Iver E. Anderson, Jeffrey A. Moore
Abstract: A filter membrane and a process for making the filter membrane are provided. The filter membrane comprises a metal substrate having a filtering layer thereon comprising sintered ultra-fine particles of metal or ceramic compounds. The filtering layer preferably has an average pore size of from about 30 nanometers to about 200 nanometers. The filter membranes can withstand pressure drops of up to about 0.6 MPa and are useful for a variety of filtering applications.
Type:
Grant
Filed:
August 17, 1993
Date of Patent:
November 15, 1994
Assignee:
Ultram International L.L.C.
Inventors:
Lev I. Trusov, Vladimir N. Lapovok, Victor I. Novikov
Abstract: Master alloys and methods of producing same are disclosed, wherein an intermetallic compound is first prepared via thermite processing, then size reduced, then mixed with other components in amounts yielding a mixture in the desired proportion for the master alloy. The mixture is compacted, then heated to produce the master alloy, which is used for making Nickel-based alloys used, (for example), in hydrogen battery electrodes.
Abstract: A composite electrode for electrochemical processing having improved high temperature properties, and a process for making the electrode by combustion synthesis. A composition from which the electrode is made by combustion synthesis comprises from about 4% to about 90% by weight of a particulate or fibrous combustible mixture which, when ignited, is capable of forming an interconnected network of a ceramic or metal-ceramic composite, and from about 10% to about 60% by weight of a particulate or fibrous filler material capable of providing the electrode with improved oxidation resistance and maintenance of adequate electrical conductivity at temperatures above 1000.degree. C. The filler material is molybdenum silicide, silicon carbide, titanium carbide, boron carbide, boron nitride, zirconium boride, cerium oxide, cerium oxyfluoride, or mixtures thereof.
Abstract: A PTC device has two electrodes affixed to opposed surfaces. The electrodes consist of a metal foil having a conductive layer on their surfaces that contact the PTC material. The conductive layer has a thermal coefficient of expansion intermediate between the thermal coefficients of expansion of the metal foil and the PTC material. The intermediate value of the thermal coefficient of expansion of the conductive layer prevents peeling of the electrodes off the PTC element due to the variation of the temperature of the PTC device resulting from repeated voltage applications. In addition, improved adhesion of the electrodes to the PTC material reduces resistance changes after repeated temperature cycling.
Abstract: It is the object of the invention to reduce the propagation of noises, in particular shifting noises, in mechanical transmissions. The invention consists in the use of a sintered shaped part formed in an individualized configuration as a noise-damped component, and in particular a gearwheel for a transmission. In the novel configuration, an axially symmetrical sintered shaped part has individual, approximately annular zones of material, for example, an inner rim zone close to the axis and an outer rim zone remote from the axis, the inner and outer rim zones having a high strength and being largely free from voids and a central region being highly porous and comparatively ductile.
Abstract: Disclosed herein is a multilayered sliding member comprising a lubricating composition comprising polytetrafluoroethylene and, as filler, 1-25 wt % of fibrous magnesium oxysulfate, fan-shaped magnesium oxysulfate or a mixture thereof, and a porous sintered metal layer formed on a steel backing,the lubrication composition being impregnated in and coated on a porous sintered metal layer formed on the steel backing.
Abstract: A silicon carbide material is made following a procedure including hot pressing to provide a finished product having a microstructure with an optimal grain size of less than 7 micrometers. The material exhibits a dominant failure mode of intergranular fracture requiring significant energy for crack propagation. The method of manufacturing is cost-effective by allowing the use of "dirty" raw materials since the process causes impurities to segregate at multi-grain boundary junctions to form isolated pockets of impurities which do not affect the structural integrity of the material. End uses include use as protective projectile-resistant armor.
Abstract: An article and method of manufacture of (Bi,Pb)-Sr-Ca-Cu-O superconductor. The superconductor is manufactured by preparing a first powdered mixture of bismuth oxide, lead oxide, strontium carbonate, calcium carbonate and copper oxide. A second powdered mixture is then prepared of strontium carbonate, calcium carbonate and copper oxide. The mixtures are calcined separately with the two mixtures then combined. The resulting combined mixture is then subjected to a powder in tube deformation and thermal processing to produce a substantially phase pure (Bi,Pb)-Sr-Ca-Cu-O superconductor.
Type:
Grant
Filed:
April 6, 1993
Date of Patent:
October 11, 1994
Assignee:
University of Chicago
Inventors:
Stephen E. Dorris, Roger B. Poeppel, Barton C. Prorok, Michael T. Lanagan, Victor A. Maroni
Abstract: A surface hardened aluminum part having excellent heat resistance and abrasion resistance obtained by forming, on the surface of an aluminum base material, an alloy layer that has a uniform composition and uniform hardness, being free from cracks. An aluminum alloy powder made of aluminum and metals each of which forms an intermetallic compound of high hardness with aluminum is prepared. This aluminum alloy powder is supplied onto the aluminum base material and the aluminum or aluminum alloy contained in the aluminum base material is alloyed with the aluminum alloy powder using a high-density energy heat source to form an alloy layer. The alloy layer thus formed has an intermetallic compound of high hardness uniformly distributed throughout the layer so that the hardness of the alloy layer is uniform and cracking is unlikely to occur.
Abstract: A method and apparatus for fabricating three-dimensional objects according to the selective laser sintering process are disclosed. In order to reduce inconsistencies in structural and textural integrity, and in thermal effects that can cause distortion, methods for ensuring that overlapping laser scans are accomplished in a consistent manner relative to the thermal flow from the sintered locations are utilized. Methods are disclosed for achieving this by limiting the extent to which the laser scans object areas in the powder layers so that the time-to-return for adjacent overlapping scans is minimized; such minimization results in significantly less variation in the time-to-return overall.
Type:
Grant
Filed:
December 18, 1992
Date of Patent:
October 4, 1994
Assignee:
DTM Corporation
Inventors:
Joseph J. Beaman, Joseph C. McGrath, Frost R. R. Prioleau
Abstract: In accordance with a method of producing metal sinter bodies, the bodies are provided with degassing openings which are made preferably before sintering of an initial press body part.
Abstract: A method for improving the long-term color stability of jet fuel and jet fuel blends containing nitrogen compounds, by intimately mixing the jet fuel with a quantity of concentrated sulfuric acid sufficient to remove at least about ninety percent (90%) of said nitrogen compounds during a contact time equal to less than five (5) minutes, separating the jet fuel from the concentrated sulfuric acid, mixing the jet fuel with an aqueous caustic solution to remove residual acid from the jet fuel, separating the jet fuel from the aqueous caustic solution, mixing the jet fuel with water, and separating the jet fuel from the water.