Other

Ut-battelle, Inc.

The United States of America As Represented by the Department of Energy

Karren Leslie More

Ramesh Subramanian

Martin R Myers

Srinath Viswanathan

Michael J Warwick

Yongching Chen

Quingyou Han

Orlando Rios

Philip J Maziasz

Felix Leonard Paulauskas

Paul A Menchhofer

Michael Leonard Santella

Bruce A Pint

Wyatt Evan Tenhaeff

Robert W Swindeman

Michael Alan McGuire

Woo Y Lee

Edgar Lara-Curzio

A method for producing a carbon fiber, the method comprising: (i) subjecting a continuous carbon fiber precursor having a polymeric matrix in which strength-enhancing particles are incorporated to a stabilization process during which the carbon fiber precursor is heated to within a temperature range ranging from the glass transition temperature to no less than 20&#xb0; C. below the glass transition temperature of the polymeric matrix, wherein the maximum temperature employed in the stabilization process is below 400&#xb0; C., for a processing time within said temperature range of at least 1 hour in the presence of oxygen and in the presence of a magnetic field of at least 1 Tesla, while said carbon fiber precursor is held under an applied axial tension; and (ii) subjecting the stabilized carbon fiber precursor, following step (i), to a carbonization process. The stabilized carbon fiber precursor, resulting carbon fiber, and articles made thereof are also described.

Low temperature stabilization process for production of carbon fiber having structural order

A wrought stainless steel alloy composition includes 12% to 25% Cr, 8% to 25% Ni, 0.05% to 1% Nb, 0.05% to 10% Mn, 0.02% to 0.15% C, 0.02% to 0.5% N, with the balance iron, the composition having the capability of developing an engineered microstructure at a temperature above 550&#xb0; C. The engineered microstructure includes an austenite matrix having therein a dispersion of intragranular NbC precipitates in a concentration in the range of 10to 10precipitates per cm.

Wrought stainless steel compositions having engineered microstructures for improved heat resistance

A method for forming light-weight composite metal castings incorporating metallurgically bonded inserts for a variety of applications. Castings formed by the invention have particular utility as components of an internal combustion engine. A casting method includes the step of coating the insert with a first layer under conditions including sufficient temperature to cause a portion of the layer to be sacrificed by dissolving into the cast metal material while leaving at least a portion of the first layer as a diffusion barrier between the insert and the cast material. The molten casting material is treated and handled to keep the hydrogen content below 0.15 and preferably below 0.10 parts per million. The casting step takes place under a protective gas environment of dry air, argon or nitrogen with a moisture content of less than 3 parts per million.

Metallurgical bonding of coated inserts within metal castings

A method for forming light-weight composite metal castings incorporating metallurgically bonded inserts for a variety of applications. Castings formed by the invention have a particular utility as components of an internal combustion engine. A casting method includes the step of coating the insert with a first layer which is followed by coating a second layer and concluded by a casting step under conditions including sufficient temperature to cause the second coated layer to be sacrificed by dissolving into the cast metal material while leaving at least a portion of the first layer as a diffusion barrier between the insert and the cast material. The molten casting material is treated and handled to keep the hydrogen content below 0.15 and preferably below 0.10 parts per million. The casting step takes place under a protective gas environment of dry air, argon or nitrogen with a moisture content of less than 3 parts per million.

Mettallurgical bonding of inserts having multi-layered coatings within metal castings

A ceramic-matrix composite having a multilayered interfacial coating adapted to protect the reinforcing fibers from long-term oxidation, while allowing these to bridge the wake of advancing cracks in the matrix, is provided by selectively mismatching materials within adjacent layers of the interfacial coating, the materials having different coefficients of thermal expansion so that a low toughness interface region is created to promote crack deflection either within an interior layer of the mismatched interfacial coating or between adjacent layers of the mismatched interfacial coating.

Oxidation-resistant interfacial coating for fiber-reinforced ceramic

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Knoxville, TN, United States of America

Karren Leslie More