Swagelok Company

Case Western Reserve University

Max-planck-gesellschaft Zur F&#xf6;rderung Der Wissenschaften E. V.

Frank Ernst

Peter C Williams

Steven V Marx

Anna V Agaponova

Arthur H Heuer

Christina Semkow

Harold Kahn

Cyprian Adair William Illing

Todd Johns

Ronald Edmonson

Zhen Li

Zhe Ren

Tilo Gödecke

Anna V Agoponova

Arthur Heuer

A method for low-temperature interstitial case formation on a self-passivating metal workpiece includes exposing the workpiece in a heated gaseous environment comprising oxygen to pyrolysis products of a nonpolymeric reagent comprising nitrogen and carbon.

Activation of self-passivating metals using reagent coatings for low temperature nitrocarburization in the presence of oxygen-containing gas

A workpiece made from a self passivating metal and having one or more surface regions defining a Beilby layer as a result of a previous metal shaping operation is activated for subsequent low temperature gas hardening by exposing the workpiece to the vapors produced by heating an oxygen-free nitrogen halide salt.

Enhanced activation of self-passivating metals

A carburization method for steel is contemplated, with austenitic stainless steel showing particular promise. The surface is first passivated with an acidic solution and then subjected to low temperature (between &#x2dc;350 to 550&#xb0; C. or between &#x2dc;650 to 1,000&#xb0; F.) carburization in the presence of a concentrated carbon solution (e.g., carbon monoxide, hydrogen gas, and nitrogen gas), followed by a repeated cycle of passivation and carburization under identical conditions but for a comparatively shorter period of time relative to the first cycle. The carburized surface is allowed to cool and cleaned, after which the resulting surface is shown to have ultrahigh tensile strength, increased interatomic bonding strength, and lowered electrical and thermal conductivity. To the extent this method can be employed to completely saturate and penetrate the workpiece (e.g., a foil), the resultant material and article are formed entirely from a novel composition.

Metal carburization process to produce a uniform, concentrated solid solution of interstitial carbon workpiece and articles made from same

A process for surface activation or depassivation of an article, in particular an alloy, by immersion of the alloy in an aqueous acid solution. The surface activation methods of the present invention can be performed during a relatively short period of time and achieve reductions in production costs and provide environmental friendliness as compared to prior art processes. In a further embodiment, after surface activation, the article is immersed in a second liquid that prevents re-formation of a passivating oxide layer on the surface of the article. In a further embodiment the surface-activated alloys are subjected to surface engineering by a process that infuses carbon or nitrogen through the surface at a temperature sufficiently low to suppress precipitation of carbides or nitrides.

Alloy surface activation by immersion in aqueous acid solution

The present invention relates to the use of phase equilibria as shown in the phase diagram of Cu&#x2014;In&#x2014;Se for the preparation of solid compositions. Further, a new method for directly obtaining &#x3b1; CulnSe2 from a liquid phase, preferably as a single phase composition and novel single phase &#x3b1; CulnSe2 compositions are provided.

Preparation of compounds based on phase equilibria of Cu-In-Se

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Cleveland, OH, United States of America

Frank Ernst