Abstract: Methods and systems for controlling gas atmospheres in three-dimensional laser printing and weld overlay consolidation operations using metallic powders are provided. In one or more embodiments, such systems and methods comprise a printing chamber or laser weld overlay system, a gas supply system, a feed powder system, and one or more sensors employed to control the printing or welding operation. The methods and systems of the invention employ one or more inert gases having a purity greater than or equal to 99.

Abstract: Described herein are a method, an apparatus, and a system for metal processing that improves one or more properties of a sintered metal part by controlling the process conditions of the cooling zone of a continuous furnace using one or more cryogenic fluids. In one aspect, there is provided a method comprising: providing a furnace wherein the metal part is passed therethough on a conveyor belt and comprises a hot zone and a cooling zone wherein the cooling zone has a first temperature; and introducing a cryogenic fluid into the cooling zone where the cryogenic fluid reduces the temperature of the cooling zone to a second temperature, wherein at least a portion of the cryogenic fluid provides a vapor within the cooling zone and cools the metal parts passing therethrough at an accelerated cooling rate.

Abstract: Methods and systems for controlling gas atmospheres in three-dimensional laser printing and weld overlay consolidation operations using metallic powders are provided. In one or more embodiments, such systems and methods comprise a printing chamber or laser weld overlay system, a gas supply system, a feed powder system, and one or more sensors employed to control the printing or welding operation. The methods and systems of the invention employ one or more inert gases having a purity greater than or equal to 99.

Abstract: A nozzle and process are set forth for contacting a cryogenic liquid and a gas, and discharging the resulting fluid through the nozzle. In one embodiment, the ratio of the discharged fluid's liquid component to its gaseous component is controlled as a function of the gas pressure.

Abstract: Described herein is a method that can be used for heat treating a metal in at least one of the following processes: carburizing, carbonitriding, nitrocarburizing, and neutral carbon potential annealing operations that are used in a 1 atmosphere pressure furnace and in an atmosphere that is oxygen free and comprises nitrogen and at least one hydrocarbon.

Abstract: A fluid spray device system (1) that maintains a resultant fluid discharge, or a material onto which the resultant fluid is discharged, within a predetermined range of a set-point temperature by regulating the flow rate of a throttling gas using a proportional valve (22). The resultant fluid has throttling gas and cryogenic fluid components. Both the throttling gas and cryogenic fluid are preferably supplied from a single tank (11) and the cryogenic fluid supply is pressure-regulated and includes a triaxial delivery hose (33) having a return line with a back-pressure regulator (54).

Abstract: A method and apparatus for nitriding of highly-alloyed metal article is disclosed herein. In one embodiment, the method and apparatus uses at least one nitrogen source gas such as nitrogen and/or ammonia in an oxygen-free nitriding gas atmosphere, with small additions of one or more hydrocarbons. In this or other embodiments, the method and apparatus described herein is applicable to metal articles comprising iron, nickel and cobalt based alloys and which tend to form passive oxide films on at least a portion of their surface, heated to and nitrided at a certain temperature without prior surface preparation. The apparatus includes an external gas injector comprising 50-60 Hz AC, high voltage/low-current arc discharge electrodes, activating the nitriding atmosphere stream on its way from source to nitriding furnace.

Abstract: A method of quenching a material by injecting a cryogenic fluid into a cooling stream and simultaneously venting gas from the cooling stream, in order to maintain a desired target pressure in a chamber containing the material. In a examplary application of the method, the quenching is a step in the heat-treatment of a metal and the chamber is part of a vacuum furnace. Also disclosed is a method of supplying a cryogenic fluid to a process in which the amount of cryogenic fluid necessary to perform the process is transferred from a storage vessel to a supply vessel via a supply line, after which the supply line is closed. An elevated pressure is maintained by vaporization of a relatively small amount of the cryogenic fluid that is allowed to build in a pressure vessel that is in fluid communication with the supply vessel.

Abstract: A process for the thermal deposition coating of a workpiece is provided that comprises the steps of: thermally depositing a coating on a metallic surface of a workpiece from a deposition head wherein at least one condition selected from the group of: coating deposition rate onto said surface, relative motion between the surface and said deposition head, and cryogenic coolant application rate onto said workpiece is controllable; substantially simultaneously measuring temperatures at a plurality of locations over the metallic surface of the workpiece; determining an average temperature of the temperatures measured in step (b); comparing the average temperature to a preselected minimum temperature and a preselected maximum temperature for the workpiece; and adjusting at least one of the controllable conditions if said average temperature is not between the preselected minimum temperature and the preselected maximum temperature for the workpiece.

Abstract: A method and apparatus for galvanizing an elongated object, such as, but not limited to, a metal strip, wire, or rod, using gaseous nitrogen, a mixture of gaseous and liquid nitrogen, and combinations thereof is described herein.

Abstract: A method of quenching a material by injecting a cryogenic fluid into a cooling stream and simultaneously venting gas from the cooling stream, in order to maintain a desired target pressure in a chamber containing the material. In a examplary application of the method, the quenching is a step in the heat-treatment of a metal and the chamber is part of a vacuum furnace. Also disclosed is a method of supplying a cryogenic fluid to a process in which the amount of cryogenic fluid necessary to perform the process is transferred from a storage vessel to a supply vessel via a supply line, after which the supply line is closed. An elevated pressure is maintained by vaporization of a relatively small amount of the cryogenic fluid that is allowed to build in a pressure vessel that is in fluid communication with the supply vessel.

Abstract: Described herein is a method that can be used for heat treating a metal in at least one of the following processes: carburizing, carbonitriding, nitrocarburizing, and neutral carbon potential annealing operations that are used in a 1 atmosphere pressure furnace and in an atmosphere that is oxygen free and comprises nitrogen and at least one hydrocarbon.

Abstract: A process for treating a workpiece having the steps of: altering the temperature of a workpiece surface wherein at least one condition selected from the group of: thermal treatment rate, relative motion between the surface and said thermal treatment rate, coolant flow rate onto said surface, heating flow rate onto said surface and the relative speed between the heating means or the cooling means and the surface is controllable; simultaneously measuring temperatures at a plurality of locations over the surface of the workpiece; determining an average temperature of the temperatures measured; comparing the average temperature to preselected minimum and maximum temperatures for the workpiece; and automatically adjusting at least one of, the controllable conditions if said average temperature is not between the preselected minimum and maximum temperatures for the workpiece. A system for performing a thermal treatment process and the resulting product are also provided.

Abstract: A gas injector including in which a gas is passed through high-voltage/low-current electrical discharges before being discharged into the chamber of a thermal treatment furnace. The electrical activation of the gas accelerates desirable reactions between the gas, gases in the furnace chamber, and the chamber workload. Preferably, a hot electrode is electrically charged and the other parts of the gas injector and the furnace are grounded. Also provided is a method for activating an atmosphere within the reaction chamber of a controlled-atmosphere reactor.

Abstract: A fluid spray device system (1) that maintains a resultant fluid discharge, or a material onto which the resultant fluid is discharged, within a predetermined range of a set-point temperature by regulating the flow rate of a throttling gas using a proportional valve (22). The resultant fluid has throttling gas and cryogenic fluid components. Both the throttling gas and cryogenic fluid are preferably supplied from a single tank (11) and the cryogenic fluid supply is pressure-regulated and includes a triaxial delivery hose (33) having a return line with a back-pressure regulator (54).

Abstract: An apparatus and a method are disclosed for reducing a thickness of a thermomechanically-affected layer on an as-machined surface of a hard metal workpiece being machined by a hard cutting tool exerting a thermomechanical load on a surface of the workpiece. The method involves reducing the thermomechanical load on the surface of the workpiece, and the apparatus includes a means for reducing the thermomechanical load on the surface of the workpiece.

Abstract: A method and apparatus for nitriding of highly-alloyed metal article is disclosed herein. In one embodiment, the method and apparatus uses at least one nitrogen source gas such as nitrogen and/or ammonia in an oxygen-free nitriding gas atmosphere, with small additions of one or more hydrocarbons. In this or other embodiments, the method and apparatus described herein is applicable to metal articles comprising iron, nickel and cobalt based alloys and which tend to form passive oxide films on at least a portion of their surface, heated to and nitrided at a certain temperature without prior surface preparation. The apparatus includes an external gas injector comprising 50-60 Hz AC, high voltage/low-current arc discharge electrodes, activating the nitriding atmosphere stream on its way from source to nitriding furnace.

Abstract: Described herein are a method, an apparatus, and a system for metal processing that improves one or more properties of a sintered metal part by controlling the process conditions of the cooling zone of a continuous furnace using one or more cryogenic fluids. In one aspect, there is provided a method comprising: providing a furnace wherein the metal part is passed therethough on a conveyor belt and comprises a hot zone and a cooling zone wherein the cooling zone has a first temperature; and introducing a cryogenic fluid into the cooling zone where the cryogenic fluid reduces the temperature of the cooling zone to a second temperature, wherein at least a portion of the cryogenic fluid provides a vapor within the cooling zone and cools the metal parts passing therethrough at an accelerated cooling rate.

Abstract: An apparatus and method for monitoring and/or controlling cryogenic cooling by measuring the opacity of the vapor cloud (113) generated from a cryogenic cooling device (112). The opacity is determined by measuring the reduction in intensity of a light beam (127) passed through the vapor cloud (113). The opacity measurements are used to control an operating parameter of the system, such as the cooling rate of the cryogenic cooling device (112). The opacity measurements may be normalized to compensate for variables, other than temperature of the workpiece (119) and cooling rate, which may affect the opacity of the vapor cloud (113).

Abstract: A method and apparatus for determining a non-linear cryogenic cooling profile (16) for the purpose of improving rolled product (5) uniformity based on at least one operating parameter in a cold rolling process; and generating the non-linear cryogenic cooling profile (16) as a function of throttling gas pressure.