Marko Materials, Inc.

Northeastern University

Other

Sikorsky Aircraft Corporation

Bill C Giessen

Ranjan Ray

Donald E Polk

Viswanathan Panchanathan

Clark VanTine Cooper

Krassimir Grigorov Marchev

Robert S Markiewicz

Raymond C Benn

Edward H Bittner

Harsh Vinayak

Thomas R Gilbert

Feng Chen

Bala Maheswaran

Krassimir G Marchev

Sunil V Gokhale

A nitrided metal includes a metal core with a first microstructure and a nitrogen-containing solid solution region on the metal core. The nitrogen-containing solid solution region is free of nitride compounds and includes a second microstructure which is equivalent to the first microstructure. The first microstructure and the second microstructure are a tetragonal crystal structure.

Method of plasma nitriding of alloys via nitrogen charging

A surface processing method and power transmission component includes transforming a surface region of a metal alloy into a hardened surface region at a temperature that is less than a heat treating temperature of the metal alloy. The metal alloy includes about 11.1 wt % Ni, about 13.4 wt % Co, about 3.0 wt % Cr, about 0.2 wt % C, and about 1.2 wt % Mo which reacts with the C to form a metal carbide precipitate of the form MC. The surface processing temperature, vacuum pressure, precursor gas flow and ratio, and time of processing are controlled to provide a desirable hardened surface region having a gradual transition in nitrogen concentration.

Method for processing alloys via plasma (ion) nitriding

A method of nitriding a metal includes transforming a surface region of a generally nitrogen-free metal into a nitrogen-containing solid solution surface region. A first heating process heats the surface region at a first temperature in the presence of a nitrogen gas partial pressure to form a nitrogen-charged surface portion on the surface region. A second heating process heats the surface region and nitrogen-charged surface portion at a second temperature for a predetermined time to interstitially diffuse nitrogen from the nitrogen-charged surface portion a depth into the surface region. Coincident with the second heating process, an ionized inert or reducing gas removes the nitrogen-charged surface portion. The resulting nitrogen-containing solid solution surface region has a gradual transition in nitrogen concentration.

Method of plasma nitriding of metals via nitrogen charging

A process for the oxygenation of ceramic high T.sub.c superconductors is disclosed. The superconductor is formed from a sintered powdered ceramic. Microchannels are formed in the ceramic material by embedding in the powder a plurality of wires or fibers formed of a material which is thermally removable during the sintering process to leave thin, continuous, tubular channels. After sintering, the ceramic is exposed to oxygen in a high temperature, high pressure environment. The microchannels aid in the transport of oxygen into the interior of the material by providing passages along which the oxygen travels prior to diffusing into the material. The lengths of the diffusion paths in the material are thereby greatly shortened. In another embodiment, the channels are formed after sintering and prior to oxygenation by drilling, punching, or etching.

Process for oxygenation of ceramic high T.sub.c superconductors

Amorphous metal alloys rich in noble metals prepared by rapid solidification processing are disclosed. The alloys have at least a ternary composition having the formula M.sub.a G1.sub.b G2.sub.c, wherein M is at least one element selected from the group consisting of Ag, Au, Ru, Os, Rh, Ir, Pd, and Pt, and G1 is at least one element selected from the group consisting of B, C, Cu, Ni, Si, and Be, and G2 is at least one element selected from the group consisting of Y, the lanthanides, Zr, Hf, Ca, Mg, Ti, Nb, and Ta. The subscripts a, b, and c are atomic percentages; a ranges from 70 to 90 percent, and b and c range from 5 to 15 percent each. Preferably, a is at least 80 percent and b and c are generally equal. The amorphous metal alloys are readily glass forming and thermally stable at room temperatures.

Amorphous metal alloys rich in noble metals prepared by rapid

A method of processing polycrystalline material by performing multi-axis crystal alignment utilizing anisotropies in the crystalline structure including the step of providing a polycrystalline material in a fluid suspension or malleable form having a magnetic moment. An external force to which the material is reactive is applied to align the individual crystals along a first axis. A magnetic field is applied to orient the magnetic moment of the crystals along a second axis, transverse to the first axis. The crystalline material may have a magnetic moment associated with a rare earth element of the material.

Crystal alignment technique for superconductors

Rapid solidification processing by liquid quenching is made practical for multiphase alloys having relatively large liquidus-solidus temperature intervals by a new processing technique termed 'melt mix reaction' involving chemically reacting two starting alloys in a mixing nozzle in which a melt mix reaction takes place between the chemically reactable components of the starting alloys to form submicron particles of the resultant compound in the final alloy. The mixing and chemical reaction is performed at a temperature which is at or above the highest liquidus temperature of the starting alloys but which is also substantially below the liquidus temperature of the final alloy, and as close to the solidus temperature of the final alloy as possible. Rapid solidification may be accomplished through the utilization of a melt spinning wheel or may be accomplished through the utilization of an atomizing nozzle configuration, with the rapidly solidified alloy containing a matrix with a microdispersion or a precipitate of the resulting compound contained therein. Heat treatment of the rapidly solidified final alloy may be additionally employed to produce precipitate hardening of the final alloy should such microdispersed precipitates not be formed or be formed incompletely during the rapid solidification process.

Method for rapid solidification processing of multiphase alloys having

Alloys having composition similar to commercial precipitation-hardenable stainless steels, but modified by the addition of 1.4 to 2.4 wt % boron, are disclosed. The alloys are subjected to a rapid solidification processing (RSP) technique which produces cooling rates between .about.10.sup.5 -10.sup.7 .degree.C./sec. The as-quenched RSP ribbon or powder, etc., consists primarily of a metastable crystalline solid solution phase. The metastable crystalline phases are subjected to suitable heat treatments so as to produce a transformation to a stable multiphase microstructure, which includes borides; this heat treated alloy exhibits superior mechanical properties and thermal stability in conjunction with good corrosion and oxidation resistance.

Boron stainless steel powder and rapid solidification method

New iron base alloys containing aluminum and boron are disclosed. The alloys are subjected to a rapid solidification processing (RSP) technique which produces cooling rates between .about.10.sup.5 to 10.sup.7 .degree. C./sec. The as-quenched ribbon or powder, etc consists primarily of a metastable crystalline solid solution phase. The metastable crystalline phases are subjected to suitable heat treatments so as to produce a transformation to a stable multiphase microstructure which includes borides. The heat treated alloy exhibits superior mechanical properties with good corrosion and oxidation resistance.

Iron-aluminum alloys containing boron which have been processed by rapid

New nickel rich metal alloys containing copper along with specific amounts of boron are disclosed. The alloys are subjected to rapid solidification processing (RSP) techniques which produce cooling rates between .about.10.sup.5 .degree. to 10.sup.7 .degree. C./sec. The as-quenched ribbon, powder, etc. consists primarily of a metastable crystalline solid solution phase. The metastable crystalline phases are subjected to suitable heat treatments so as to produce a transformation to a stable multiphase microstructure which includes borides. This heat treated alloy exhibits superior mechanical properties with good corrosion and/or oxidation resistance for numerous engineering applications.

Nickel base alloys which contain boron and have been processed by rapid

New iron rich metal alloys containing aluminum and copper along with specific amounts of boron are disclosed. The alloys are subjected to rapid solidification processing (RSP) technique which produces cooling rates between .about.10.sup.5 to 10.sup.7 .degree.C./sec. The as-quenched ribbon, powder etc. consists primarily of a metastable crystalline solid solution phase. The metastable crystalline phases are subjected to suitable heat treatments so as to produce a transformation to a stable multiphase microstructure which includes borides; this heat treated alloy exhibits superior mechanical properties with good corrosion and/or oxidation resistance for numerous engineering applications.

New iron-aluminum-copper alloys which contain boron and have been

New copper-rich metal alloys containing nickel along with certain specific amounts of boron are disclosed. The alloys are subjected to a rapid solidification processing (RSP) technique which produces cooling rates between .about.10.sup.5.degree. to 10.sup.7 .degree. C./sec. The asquenched ribbon, powder, etc. consists primarily of a metastable crystalline solid solution phase. The metastable crystalline phases are subjected to suitable heat treatments so as to produce a transformation to a stable multiphase microstructure, which includes borides. This heat treated alloy exhibits superior mechanical properties with good corrosion and/or oxidation resistance for numerous engineering applications.

Copper base alloys made using rapidly solidified powders and method

Iron base alloys containing chromium and refractory metals as well as 0.8 to 1.3 wt % boron are disclosed. The alloys are subjected to a rapid solidification processing (RSP) technique, producing cooling rates of about 10.sup.5 to 10.sup.7 .degree. C./sec. The as-quenched RSP ribbon, or powder, etc., consists primarily of a single phase with a body centered cubic structure. After appropriate heat treatments, the rapidly solidified alloys have a microstructure consisting of ultrafine hard particles of metallic carbides and borides and mixtures thereof dispersed in an iron-rich matrix. These alloys exhibit excellent corrosion resistance combined with high hardness, wear resistance and high temperature stability. These heat treated alloys have superior properties which make them suitable for many applications, where high strength and corrosion resistance are required, in particular at elevated temperature, e.g. high temperature bearings.

Tool steels which contain boron and have been processed using a rapid

Nickel and iron-nickel base alloys are described together with a rapid solidification process used in the preparation thereof to provide materials useful in the fabrication of parts subject to high temperature operating conditions. The alloys include commercial nickel base superalloys to which a specified amount of boron is added.

Nickel base superalloys which contain boron and have been processed by a

A method of fabricating aluminum alloys containing finely dispersed aluminum-transition metal intermetallic phases is disclosed. The alloys are subjected to melt spinning to form a brittle filament consisting in large measure of a metastable face-centered cubic solid solution; this is then pulverized to a staple or powder configuration; the power or staple is consolidated using conventional techniques. Upon heat treatment, the solid solution decomposes into a structure consisting of an aluminum alloy matrix of conventional composition containing a fine uniform dispersion of the intermetallic phase, the heat-treated alloy being ductile. The heat-treated alloys possess high strength, especially at elevated temperatures. Preferred alloys are disclosed which contain 10 to 15 wt % Fe.

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Cambridge, MA, United States of America

Bill C Giessen