Air Products and Chemicals, Inc.

Paul T Kilhefner, Iii

Diwakar Garg

Brian B Bonner

Mark A Pellman

Terrence S Hahn

Paul Anthony Mattiola

Donald P Eichelberger

David L Mitchell, Jr

Charles E Baukal, Jr

Willliam J Baxter

William J Baxter

An improved method for producing substantially moisture- and oxygen-free, nitrogen-hydrogen atmospheres suitable for annealing, hardening, brazing, and sintering ferrous and non-ferrous metals and alloys is disclosed. According to the disclosed method, suitable nitrogen-hydrogen atmosphere is produced by 1) generating a nitrogen stream containing about 0.1 to 5% residual oxygen by a known non-cryogenic air separation technique, 2) mixing it with a pre-determined but more than stoichiometric amount of hydrogen required to convert residual oxygen to moisture, 3) converting residual oxygen to moisture by reaction with hydrogen in a catalytic reactor, 4) cooling the reactor effluent stream, and 5) removing moisture from it in a regenerative sorbent dryer.

Method of producing nitrogen-hydrogen atmospheres for metals processing

A process for producing low-cost furnace atmospheres suitable for annealing and heat treating ferrous and non-ferrous metals and alloys, brazing metals and ceramics, sealing glass to metals, and sintering non-ferrous metal and ceramic powders from non-cryogenically produced nitrogen containing from 0.05 to 5.0% residual oxygen is presented. The disclosed process involves 1) mixing non-cryogenically produced nitrogen with a predetermined amount of dissociated ammonia, 2) passing the mixture through a low-pressure drop catalytic reactor, 3) converting the residual oxygen to an acceptable form such as moisture and reducing the residual oxygen level to below about 10 ppm, and 4) using the resultant gaseous mixture for annealing and heat treating ferrous and non-ferrous metals and alloys, brazing metals and ceramics, sealing glass to metals, and sintering non-ferrous metal and ceramic powders. The key feature of the disclosed process involves the use of a novel low-pressure drop catalytic reactor for converting residual oxygen with dissociated ammonia to moisture.

Process for producing furnace atmospheres by deoxygenating

Increased cooling rate of an article heated to an elevated temperature is achieved by flowing an inert gas mixture of helium and another inert gas over the article under conditions of turbulent flow.

Rapid gas quenching process

Uphill quenching of metal alloys, such as aluminum alloys, is improved by conducting the heating step, after the quench-cooling step of the uphill quenching, using the elevated temperature vapor of a fluorochemical compound, preferably a perfluorocarbon compound. The vapor formed over a boiling bath of the perfluorocarbon compound comprises the heat source when it condenses on the relatively cooler alloy thus imparting its heat of condensation to the alloy.

Vapor phase uphill quenching of metal alloys using fluorochemicals

Pattern material, such as wax, is removed from an investment casting mold by vapor phase-condensation heating with a fluorochemical boiling at a temperature above the melting point of the pattern material.

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Wescosville, PA, United States of America

Paul T Kilhefner, Iii