Abstract: A burn-in apparatus for burning in a transistor used in a microwave region including a burn-in frequency signal source for supplying a signal lower in frequency than the operating frequency of the transistor and higher in frequency than the response frequency of impurities in the transistor, an input matching circuit connected between the signal source and an input of the transistor, and an output matching circuit including a load and connected to an output of the transistor.
Abstract: A remote plasma generator, coupling microwave frequency energy to a gas and delivering radicals to a downstream process chamber, includes several features which, in conjunction, enable highly efficient radical generation. In the illustrated embodiments, more efficient delivery of oxygen and fluorine radicals translates to more rapid photoresist etch or ash rates. A single-crystal, one-piece sapphire applicator and transport tube minimizes recombination of radicals in route to the process chamber and includes a bend to avoid direct line of sight from the glow discharge to the downstream process chamber. Microwave transparent cooling fluid within a cooling jacket around the applicator enables high power, high temperature plasma production. Additionally, dynamic impedance matching via a sliding short at the terminus of the microwave cavity reduces power loss through reflected energy. At the same time, a low profile microwave trap produces a more dense plasma to increase radical production.
Abstract: A process gas decomposition reactor featuring two intertwined helical coils surrounding a gas flow path. Each of the two coils is energized by a separate magnetron having an associated waveguide and an inductive structural element which couples the microwave energy into the coil. The magnetic flux lines from the coil serve to confine ions and electrons within the coil, causing collisions and hence ionization of gas entering a flow path through the coil. The gas, containing HFCs and PFCs is broken down by such collisions with ions and electrons within the gas plasma. The gas displaced at the end of the coil contains decomposition products from the HFCs and PFCs.
Abstract: A toploading weighing instrumentality which determines loss on drying by a cylindrical microwave. The cylindrical cavity of the microwave includes a power supply, a magnetron, a power module operatively coupled between said power supply and said magnetron for driving said magnetron, a wave guide communicating with the magnetron and with a microwave containment chamber for delivering energy thereto, at least one microwave energy sensor for sensing microwave energy or magnetic and/or electric field strength within the chamber for controlling, inter alia, the loss on drying process of the sample being assayed and determining when the drying process is complete. A precision electronic balance is operatively disposed within the microwave chamber for allowing a specimen being assayed to be weighed. In addition, a ventilation chamber is provided for venting moisture from the microwave chamber.
Type:
Grant
Filed:
May 27, 1998
Date of Patent:
June 19, 2001
Assignee:
Denver Instrument Company
Inventors:
Robert F. Scalese, Thomas B. Taylor, Tim Holzschuh, Douglas E. Harbert, Thomas G. Playen, Martin L. Maple, Jan Claesson
Abstract: A method for separating and recovering components includes the steps of providing at least a first component bonded to a second component by a microwave absorbent adhesive bonding material at a bonding area to form an assembly, the bonding material disposed between the components. Microwave energy is directly and selectively applied to the assembly so that substantially only the bonding material absorbs the microwave energy until the bonding material is at a debonding state. A separation force is applied while the bonding material is at the debonding state to permit disengaging and recovering the components. In addition, an apparatus for practicing the method includes holders for the components.
Type:
Grant
Filed:
May 6, 1999
Date of Patent:
April 3, 2001
Assignee:
BWXT Y-12 L.L.C.
Inventors:
Marvin S. Morrow, Donald E. Schechter, Clyde L. Calhoun, Jr.
Abstract: Electronic components are bonded to an electronic circuit board with a lead-free solder. The bonded structure is cooled from a temperature close to the liquids temperature of the solder to a temperature close to the solids temperature of the solder at a first cooling rate of about 10 to 20° C./second, followed by cooling the bonded structure to a temperature lower than the solids temperature of the solder at a second cooling rate of about 0.1 to less than 5° C./second.
Abstract: A method of producing a consolidated composite wood product composed of discrete wood elements and a binder by forming a layup and preheating only a central longitudinal portion of the layup by application of microwave energy across the longitudinal axis and then pressing to consolidate the layup and applying further microwave energy in a direction perpendicular to the direction of the application of the preheating microwave energy through the sides of the compressed layup in the press.
Type:
Grant
Filed:
July 3, 2000
Date of Patent:
March 13, 2001
Assignee:
Trus Joist MacMillan Limited
Inventors:
Mark Trelawny Churchland, Robert Leeson Pike, Norbert Kott
Abstract: An interpretive system architecture for a seamless transfer of energy to a physical, chemical, or thermodynamic process stream, or microwave oven. The interpretive system architecture overlays the operational finctions of the process stream or host microwave oven to interpret, control, and implement user independent commands. The interpretive system has at least one interpretive base class for providing operational instance to the process stream or host microwave oven. The interpretive system receives an indicia, the indicia being expressive of an externally derived predetermined compiled code disposed on the surface of a specimen, or food package, or associated thereto, the indicia communicating via at least one data entry mechanism to the process stream or host microwave oven. The interpretive system interprets the data or code and transforms it into user independent commands.
Type:
Grant
Filed:
October 8, 1999
Date of Patent:
March 6, 2001
Assignee:
Microwave Science, LLC
Inventors:
Steven J. Drucker, David Marcel Raynault
Abstract: The invention relates to a process for the production of boards of wood-based material from a mixture of lignocellulose- and/or cellulose-containing particles mixed with a binder, the mat or pressed stock being preheated by means of high-frequency (HF) or microwave (MW) energy and, after transfer into a single or multi-platen press or a continuously operating press, being pressed and cured by the application of pressure and heat.
Type:
Grant
Filed:
May 4, 1998
Date of Patent:
January 23, 2001
Assignee:
Maschinenfabrik J. Dieffenbacher GmbH & Co.
Inventors:
Friedrich B. Bielfeldt, Werner Hoffmann
Abstract: A method for recovering metals from metals-containing wastes, and vitrifying the remainder of the wastes for disposal. Metals-containing wastes such as circuit boards, cathode ray tubes, vacuum tubes, transistors and so forth, are broken up and placed in a suitable container. The container is heated by microwaves to a first temperature in the range of approximately 300-800.degree. C. to combust organic materials in the waste, then heated further to a second temperature in the range of approximately 1,000-1,550.degree. C. at which temperature glass formers present in the waste will cause it to melt and vitrify. Low-melting-point metals such as tin and aluminum can be recovered after organics combustion is substantially complete. Metals with higher melting points, such as gold, silver and copper, can be recovered from the solidified product or separated from the waste at their respective melting points. Network former-containing materials can be added at the start of the process to assist vitrification.
Type:
Grant
Filed:
November 25, 1998
Date of Patent:
November 7, 2000
Assignees:
The United States of America as represented by the United States Department of Energy, University of Florida
Inventors:
George G. Wicks, David E. Clark, Rebecca L. Schulz
Abstract: A cooking appliance performs cooking which is remotely controlled, based on information relating to the object to be heated, as the information is transmitted to the appliance's computer from a management's computer. The cooking appliance can also cook any part of food in the cooking chamber locally.
Type:
Grant
Filed:
March 22, 1999
Date of Patent:
October 24, 2000
Assignee:
Matsushita Electric Industrial Co., Ltd.
Inventors:
Takashi Kashimoto, Koji Yoshino, Yasuo Yoshimura, Hiroyoshi Nomura, Makoto Shibuya, Shigeo Yoshida
Abstract: There is provided a new and useful method and apparatus for the controlled non-pyrolytic reduction of organic material comprising subjecting the material to microwave radiation in a reducing atmosphere.
Abstract: This disclosure sets forth a microwave sintering process for green oxide particles introduced from a source such as a hopper or a container, a downwardly directed funnel and a discharge outlet from the funnel. Particles are introduced into an elongate rotatable tube. The tube is inclined at a controlled angle. Particles traverse the tube, passing through a central heating zone between inlet and outlet. The time interval of the particles in the heating zone is controlled by adjustment of the angle of inclination, particle size, and rotation rate to assure that all particles are processed and converted from green to sintered oxide particles.
Abstract: A microwave vessel system for external and noninvasive pressure monitoring and control is disclosed. The system comprises a reaction vessel formed of a material that is transparent to microwave radiation, with the reaction vessel including a portion that is movable under pressure generated by a chemical reaction inside the vessel while maintaining the reaction sealed inside the vessel. A sensor is adjacent to the movable portion of the vessel for detecting the motion of the movable portion as the portion responds to pressure generated inside the vessel. The system includes a structure for maintaining the sensor against the movable portion while microwaves are applied to the vessel so that the movement of the movable portion under pressure is detected by the sensor.
Type:
Grant
Filed:
September 15, 1997
Date of Patent:
July 11, 2000
Assignee:
CEM Corporation
Inventors:
James Edward Thomas, Wyatt Price Hargett, Jr., Edward Earl King
Abstract: Microwave radiation, perhaps with microwave absorbing materials, is utilized to provide heating of partially formed integrated circuits in a variety of circumstances.
Abstract: A method enabling controlled selective heating of workpiece components during microwave brazing. Two workpiece components are joined by melting an adhesion interlayer material between the two components. An indication of when the interlayer has melted is provided. The temperature difference across the braze assembly is monitored and adjusted via a feedback loop to reduce stresses in the braze joint resulting in a stronger braze joint.
Type:
Grant
Filed:
January 16, 1998
Date of Patent:
April 25, 2000
Assignee:
California Institute of Technology
Inventors:
Martin Barmatz, Henry W. Jackson, Robert P. Radtke
Abstract: When drying of garbage is started, the opening and closing valve 61 is opened, and at the same time the processing tank 21 is heated by the heater 31. Due to the foregoing, temperatures in the processing tank 21 and the heating chamber 30 are raised and water contained in garbage in the processing tank 21 starts evaporating. At a point of time when the heating chamber 30 and the condensing chamber 40 are filled with this steam, the opening and closing valve 61 is closed, and the fan 50 is operated, so that steam in the condensing chamber 40 is cooled and condensed. Therefore, steam generated in the heating chamber 30 flows into the condensing chamber 40, and pressure in the heating chamber 30 becomes negative and the boiling point is lowered. Accordingly, it is possible to evaporate water at a low temperature.
Abstract: The present disclosure is directed to a method of converting green particles to form finished particles. The apparatus used for sintering incorporates an elongate hollow tube, an insulative sleeve there about to define an elevated temperature zone, and a microwave generator coupled through a wave guide into a microwave cavity incorporated the tube. The particles are moved through the tube at a controlled rate to assure adequate exposure to the microwave radiation. Another form sintered a solid part in a cavity or mold.
Type:
Grant
Filed:
July 26, 1996
Date of Patent:
December 21, 1999
Assignees:
Dennis Tool Corporation, The Penn State Research Foundation
Inventors:
Rustum Roy, Dinesh Agrawal, Jiping Cheng, Mahlon Dennis, Paul D. Gigil
Abstract: Herbs are dried by applying microwave power to herbs in a chamber under reduced or negative pressure to reduce the moisture content of the herbs without significantly damaging the flavor of the dried herbs and produce a dried herb having a flavor more closely approaching the flavor of fresh herbs than dried herbs produced by conventional processes.
Type:
Grant
Filed:
May 20, 1998
Date of Patent:
September 28, 1999
Assignee:
The University of British Columbia
Inventors:
Timothy Douglas Durance, Dragan Macura, Richard Scholmer Meyer, Alex N. Yousif, Christine H. Scaman, Jianhua (Linda) Wang
Abstract: A method and apparatus for applying microwaves to flowable materials within a centrifuge are disclosed. The simultaneous application of microwaves and centrifugation to flowable materials may be utilized to rapidly separate immiscible components from emulsions and dispersions. Microwaves are guided along a waveguide structure within the centrifuge. A meandering path for the waveguide is chosen through the interior of the centrifuge and through the flowable material being centrifuged. Gradual variation in the radial distance of the waveguide from the axis of the centrifuge produces a gradual filling of the cross-section of the waveguide along its length, forming a gentle microwave beach within the waveguide. Excellent microwave coupling and power deposition into the flowable material results. There is no need to contain the flowable material behind a dielectric barrier, normally placed between the incident microwaves and the flowable material, since confinement is provided by centrifugal forces.
Abstract: A method of microwave assisted chemical reaction includes providing a microwavable reaction vessel which contains at least one material in a sample. The sample is heated by microwave energy to elevate the temperature of the reagent and at least partially volatilize the sample to establish a gas phase within the vessel followed by positive cooling of the gas phase to reduce the temperature and responsively reduce the pressure of the gas phase without effecting substantial cooling of the liquid phase. The method may involve employing cooling exteriorly of and adjacent to the gas phase containing portion of the vessel or cooling by means of a coolant flowing within coils disposed in the interior of the vessel or both. The process is preferably a continuous process. The apparatus may be a vessel transparent to microwave energy for receiving the sample. The vessel has space overlying the liquid phase containing portion for a gas phase.
Abstract: The invention calls for a discrete material (1) such as a gas, a liquid or a living being, to be exposed to electromagnetic radiation from a large-area irradiator (2) causing the molecules to resonate at their natural frequency and hence to become warmer. In order to lower the temperature of the material (1), the radiant energy emitted by its is extracted via a receive antenna (5), resulting in a loss in energy and hence cooling of the material. Working in an enclosed fluid-filled space, the fluid can also be included, by suitable choice of radiation spectrum, in the resonance interaction producing the warming or cooling effect.
Abstract: A microwave plasma assisted method and system for heating and joining materials. The invention uses a microwave induced plasma to controllably preheat workpiece materials that are poorly microwave absorbing. The plasma preheats the workpiece to a temperature that improves the materials' ability to absorb microwave energy. The plasma is extinguished and microwave energy is able to volumetrically heat the workpiece. Localized heating of good microwave absorbing materials is done by shielding certain parts of the workpiece and igniting the plasma in the areas not shielded. Microwave induced plasma is also used to induce self-propagating high temperature synthesis (SHS) process for the joining of materials. Preferably, a microwave induced plasma preheats the material and then microwave energy ignites the center of the material, thereby causing a high temperature spherical wave front from the center outward.
Type:
Grant
Filed:
January 5, 1996
Date of Patent:
December 8, 1998
Assignee:
California Institute of Technology
Inventors:
Martin Barmatz, Tzu-yuan Ylin, Henry Jackson
Abstract: A method for recovering metals from metals-containing wastes, and vitrifying the remainder of the wastes for disposal. Metals-containing wastes such as circuit boards, cathode ray tubes, vacuum tubes, transistors and so forth, are broken up and placed in a suitable container. The container is heated by microwaves to a first temperature in the range of approximately 300.degree.-800.degree. C. to combust organic materials in the waste, then heated further to a second temperature in the range of approximately 1,000.degree.-1,550.degree. C. at which temperature glass formers present in the waste will cause it to melt and vitrify. Low-melting-point metals such as tin and aluminum can be recovered after organics combustion is substantially complete. Metals with higher melting points, such as gold, silver and copper, can be recovered from the solidified product or separated from the waste at their respective melting points.
Type:
Grant
Filed:
January 19, 1996
Date of Patent:
December 1, 1998
Assignee:
The United States of America as represented by the United States Department of Energy
Inventors:
George G. Wicks, David E. Clark, Rebecca L. Schulz
Abstract: A method for heating, forming and tempering a glass sheet including the steps of heating at least one glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, forming the glass sheet to a predetermined configuration, and cooling an outer surface of the glass sheet to at least a third predetermined temperature to temper the glass sheet.
Type:
Grant
Filed:
November 12, 1997
Date of Patent:
October 27, 1998
Assignee:
Ford Global Technologies, Inc.
Inventors:
Premakaran Tucker Boaz, Gary W. Sitzman
Abstract: In accordance with the present invention, a vending machine includes a number of failure control devices that monitor and control the functioning of the various components in the vending machine to ensure uniform quality of food products to be sold to a customer. One specific embodiment includes plurality of oven failure control devices, a freezer failure control device and a power failure control device. When a microcontroller in the vending machine determines the occurrence of a failure, the microcontroller displays a failure message on a customer display and discontinues vending food until the failure is corrected, for example, by an operator. In another aspect of this invention, the vending machine includes a mechanism for operating a door of a refrigeration compartment of the vending machine. The mechanism includes a motor driven rotary link coupled to a roller that moves in a slot of the door.
Type:
Grant
Filed:
April 20, 1995
Date of Patent:
September 1, 1998
Assignee:
KRh Thermal Systems
Inventors:
Paul T. Rudewicz, Thom Thomas, Mark A. Hopkins, Robert K. Chan
Abstract: Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy.
Type:
Grant
Filed:
March 29, 1996
Date of Patent:
August 25, 1998
Assignees:
Lambda Technologies Inc., Lockheed Martin Energy Research Corporation
Inventors:
Robert J. Lauf, April D. McMillan, Felix L. Paulauskas, Zakaryae Fathi, Jianghua Wei
Abstract: A rapid thermal processing method for a ceramic thin film which is capable of carrying out a uniform heating of a large sized wafer, and of achieving a rapid temperature elevation, and of enhancing a crystallinity of a deposited thin film, wherein a thin film-coated material is disposed on a support to rapidly heat the thin film by the application of microwaves, the temperature is measured with a temperature measuring unit, and the generation of the microwaves is halted at a required temperature.
Type:
Grant
Filed:
November 27, 1996
Date of Patent:
August 18, 1998
Assignee:
Korea Institute of Science and Technology
Inventors:
Tae Song Kim, Hyung Jin Jung, Do Kyung Kim, Yoon Chang Kim
Abstract: A method for heating a glass sheet includes the steps of heating a glass sheet to a first predetermined temperature and applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature to allow the glass sheet to be formed.
Abstract: Polyaromatic hydrocarbons are highly carcinogenic ubiquitous industrial wastes. In this Invention, concentrations of said wastes are diminished by microwave-assisted pyrolysis. Prior to exposure to microwave radiation, said wastes are covered with a non-combustible material consisting of loose, discrete particles like sand. Susceptors may be added to the waste prior to radiation. Volatiles from the process can be absorbed in a susceptor like granulated activated charcoal. When saturated, this granulated activated charcoal is added to the said wastes in a subsequent treatment.
Abstract: A method for heating and forming a glass sheet includes the steps of heating a glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, cooling an outer surface of the glass sheet to at least a third predetermined temperature and forming the glass sheet using forming rollers to a predetermined configuration.
Abstract: The invention provides methods and apparatus for sterilizing articles. According to one exemplary method, at least one article is placed into a chamber and a vacuum is applied to the chamber. After the pressure within the chamber is sufficiently reduced, water vapor is introduced into the chamber and electromagnetic radiation energy is applied to produce a plasma. In one particularly preferable aspect, the chamber is allowed to reach a static condition before the water vapor is introduced. In this way, the water vapor is able to equally distribute itself throughout the volume of the chamber so that an equally distributed plasma can be produced upon application of the electromagnetic radiation energy.
Type:
Grant
Filed:
December 29, 1994
Date of Patent:
May 27, 1997
Inventors:
Clinton G. Graves, Clinton G. Graves, II
Abstract: There is provided a method and apparatus for forming meat analog products and for texturizing a doughmass wherein the ingredients are mixed, passed through a conduit having a decreasing cross-sectional area while the doughmass is heated therein, the heating being done such that a greater heat intensity is applied to the center of the doughmass than to the doughmass adjacent the walls of the conduit.
Type:
Grant
Filed:
February 21, 1996
Date of Patent:
March 4, 1997
Inventors:
Peter W. De Ruyter, Noel Almey, Josef Slanik, Wesley W. Teich
Abstract: A barbecue appliance capable of cooking a variety of foods by disposing a rotary grill in which food is held vertically within a cooking chamber between heating members provided therein and rotating the rotary grill between the heating members, so that an optimum cooking state is obtained. The barbecue includes a cooking unit and a rotary grill which may be inserted into the cooking unit. The cooking unit has an outer casing provided with an elongated top opening and having a removable drip reservoir provided in the bottom thereof, a main frame encased by the outer casing and having a bottom wall and side walls defining therewithin a vertical cooking chamber opened and its top, heating members disposed on both sides of the cooking chamber, a drive section having a driving gear extended to the inside of the cooking chamber, a solenoid-releasable lifting and lowering mechanism for lifting and lowering the rotary grill in the cooking chamber.
Abstract: A susceptor according to the present invention includes a substrate having physical properties so that melting and size deformation of the substrate occur in response to microwave absorption by the susceptor. A metalized layer is coupled to the substrate, and supporting means is provided for supporting the substrate and the metalized layer.
Abstract: The described invention is directed to microwave methods for burning-in, electrical stressing, thermal stressing and reducing rectifying junction leakage current in fully processed semiconductor chips individually and at wafer level, as well as burning in and stressing semiconductor chip packaging substrates and the combination of a semiconductor chip mounted onto a semiconductor chip packaging substrate. Microwaves burn-in devices in a substantially shorter period of time than conventional burn-in techniques and avoid the need for special workpiece holders which are required by conventional stress and burn-in techniques. Additionally, microwave methods are described for reducing the leakage current of recitfying junctions, such as PN junctions and Schottky barrier diode junctions of semiconductor devices on fully processed semiconductor chips and wafers.
Type:
Grant
Filed:
October 27, 1992
Date of Patent:
May 21, 1996
Assignee:
International Business Machines Corporation
Inventors:
Peter E. Freiermuth, Kathleen S. Ginn, Jeffrey A. Haley, Susan J. Lamaire, David A. Lewis, Gavin T. Mills, Timothy A. Redmond, Yuk L. Tsang, Joseph J. Van Horn, Alfred Viehbeck, George F. Walker, Jer-Ming Yang, Clarence S. Long
Abstract: A method and apparatus for vending a hot food product wherein a sealed container is moved from a protective sleeve and deposited in an oven where heat is transferred to the container for initially melting a protective sealing film and then heating the food product. After the food product has been heated, the container is removed from the oven and reinserted into the protective sleeve prior to dispensing the heated food product.
Type:
Grant
Filed:
May 9, 1994
Date of Patent:
September 12, 1995
Assignee:
Patentsmith Technology, Ltd.
Inventors:
Donald P. Smith, Michael J. Dobie, Alden B. Sparman, Sr., John R. Norris
Abstract: A structure and a technique for heating hot melt adhesive by means of microwaves, to place the hot melt adhesive in a tacky state in which it adheres to an object. A preferred structure according to the invention comprises an article of manufacture (e.g., a wall hook) having a mass of the hot melt adhesive and a susceptor thereon. The article, with the adhesive and susceptor thereon, can be subjected to microwaves for a predetermined period of time, to place the mass of adhesive in a tacky state which enables the article to be attached to an object (e.g., a wall). A special container for the article is placed with the article into a microwave oven as a unit, and removed as a unit from the oven. The container enables the article to be safely and efficiently attached to the object.
Type:
Grant
Filed:
May 4, 1994
Date of Patent:
July 18, 1995
Assignee:
Nottingham Spirk Design Associates
Inventors:
John R. Nottingham, John Spirk, Craig M. Saunders, Paul E. Brokaw
Abstract: An oven for cooking by hot air impingement includes a housing defining a cooking chamber adapted to receive a food product for cooking, a hot air plenum configured and dimensioned to hold a volume of air and a conduit for providing gaseous communication therebetween. Associated with the plenum is a thermal energy source for heating gas disposed in the plenum.
Abstract: A method and apparatus defreeze, reheat and dry products in a closed chamber by moving a microwave source above a layer of product in a to-and-from motion at a specific, constant height from the product layer.
Abstract: The present invention features a UV tube detector for sensing a resonant arcing condition in a microwave environment. Where clothing or fabric is being dried in a magnetron-powered, microwave chamber, the UV tube detector is placed in proximity to the fabric. The UV tube detector senses a possible resonant arcing condition related to small metal objects hidden in the material. Upon the sensing of arcing, tile UV tube provides a signal for shutting down the magnetron power. In conjunction with UV detection, the moisture condition can be monitored during the drying cycle. At a point in the microwave heating cycle consistent with an "end of microwave heating cycle" or "near dryness", the power output of the magnetrons is reduced or terminated. The moist fabric can then be dried via reduced microwave heating and/or by normal heating methods, including, but not limited to, electrical radiant heating and convection techniques.
Abstract: A method of nitriding a refractory-nitride forming metal or metalloid articles and composite articles. A consolidated metal or metalloid article or composite is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article or composite is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article or composite is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid or composite to an article or composite of refractory nitride. In addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.
Type:
Grant
Filed:
January 10, 1992
Date of Patent:
March 15, 1994
Assignee:
Martin Marietta Energy Systems, Inc.
Inventors:
Terry N. Tiegs, Cressie E. Holcombe, Norman L. Dykes, Ogbemi O. Omatete, Albert C. Young
Abstract: An automated food vending system includes a vending machine having a plurality of stacks and dispenser mechanisms for dispensing standardized food package units, a microwave oven having a code reader located in a predetermined position in an interior cavity of the oven, and the food package units having standardized shapes corresponding to the vending stacks and to the microwave oven cavity. The food packages have a code for controlling the microwave oven printed in a predetermined position which is readable automatically by the code reader when the package unit is inserted in the oven. The dispenser mechanism has a configuration which allows it to be installed in existing vending machines for canned beverages. It may be formed as a pair of pivotable holding members spaced apart in the widthwise direction of the holding stack, or as a pair of continuous belts spaced apart in the depthwise direction of the holding stack.