Other

Technology Assessment & Transfer, Inc.

Richard Silberglitt

Frederick M Mako

Iftikhar Ahmad

Lek K Len

Edward L Paquette

The present invention is a method of joining two materials by single pulse electron radiation. The method comprises the step of disposing a first material layer adjacent to a second material layer such that an interface is disposed therebetween. Then there is the step of irradiating the interface with a pulsed electron beam such that energy of the pulsed electron beam is selectively deposited in a narrow spatial region and localized at the interface to produce an effective joint between the first and second material layers in a single pulse. Preferably, before the irradiating step, there is the step of calculating an optimum temperature profile across the interface depending on electron energy, beam current density and pulse length of the pulsed electron beam. The electron energy of the pulsed electron beam is preferably in the range of 100 keV to 10 MeV. The pulsed electron beam current density is preferably in the range of 1-1000 A/cm.sup.2. The pulsed electron beam pulse length is preferably in the range of 100 nsec (10.sup.-7 seconds) to 100 .mu.sec (10.sup.-4 seconds). If desired, there can be interlayer materials disposed between the first and second materials.

Pulsed electron beam joining of materials

A method for the production of ceramic matrix composites by chemical vapor infiltration. The method includes exposing an infiltrated preform to microwave energy, with pressure variation of the reactant gases in the processing chamber and/or temperature variation of the preform during processing, to produce substantially improved composites. The process provides higher deposition rates within the core of the ceramic matrix composite, higher densification which advantageously initiates within the interior of the ceramic matrix composite and proceeds radially outward, and a thick wall ceramic matrix composite with an overall reduced density gradient.

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Fairfax Station, VA, United States of America

Richard Silberglitt