Lawrence Livermore National Security, LLC

Gabriel Mark Guss

Manyalibo Joseph Matthews

Jeffrey Devin Bude

Alexander M Rubenchik

Isaac Louis Bass

John J Adams

Michael C Nostrand

Paul J Wegner

Masoud Bolourchi

Jeffery A Jarboe

Jay Walter Dawson

Paul H Pax

Derrek Reginald Drachenberg

William Smith

Selim Elhadj

Nicholas P Calta

Raluca A Negres

John Roehling

Sonny S Ly

Nan Shen

Jean-Baptiste Forien

Manyilibo J Matthews

Wesley John Keller

Joseph T McKeown

A system and method is disclosed for detecting anomalies in an additively manufactured part. An energy source generates a signal forming an optical beam for creating a melt pool in a layer of feedstock material being selectively fused to make a part in an additive manufacturing operation. A sensor is configured to receive a signal reflected from the melt pool. The reflected signal forms a thermal signal indicative of a temperature of the feedstock material at a known location on a layer of the feedstock material while the feedstock material is being fused at the known location. A controller receives and analyzes data relating to the received signal to determine if an anomaly exists at the known location.

System and method for in situ inspection of defects in additively manufactured parts using high speed melt pool pyrometry

The present disclosure relates to an additive manufacturing system for forming a part using a powder material. In one embodiment the system makes use of a primary heat generating subsystem to generate a fusing beam for heating and fusing at least one of select portions of a powder layer, or an entire area of a powder layer, deposited on a build plate. The system also incorporates a beam steering subsystem for steering the fusing beam over the powder layer. A supplemental heating subsystem is used to generate a wide area beam to heat a portion of the powder layer either prior to fusing, along with the fusing operation, or subsequent to fusing of the powder with the fusing beam. The wide area beam has an intensity which is insufficient to fuse the powder, and alters a microstructure of the powder layer as the powder layer is at least one of fused or as it cools, to thus relieve stress in the part.

System and method for performing laser powder bed fusion using controlled, supplemental in situ surface heating to control microstructure and residual stresses in formed part

The present disclosure relates to a laser system for processing a material. The system may make use of a laser configured to intermittently generate a first laser pulse of a first duration and a first average power, at a spot on a surface of the material being processed, and a second laser pulse having a second duration and a second peak power. The second duration may be shorter than the first duration by a factor of at least 100, and directed at the spot. The second laser pulse is generated after the first laser pulse is generated. The first laser pulse is used to heat the spot on the surface of the material, while the second laser pulse induces a melt motion and material ejection of molten material from the melt pool.

Laser drilling and machining enhancement using gated CW and short pulsed lasers

A high-power laser beam with an arbitrary intensity profile is produced. Such beam has a variety of uses including for laser materials processing such as powder bed fusion additive manufacturing. Several challenges in additive manufacturing are mitigated with the present non-uniform intensity laser profiles. Nonuniform shapes include a set of intensity pixels in a line that could print a wide stripe area instead of just a single line. One example uses the multimode interference pattern from the output of a ribbon fiber which is imaged onto a work piece. The interference pattern is controlled to allow turning on or off of 'pixels' along a line which can be used to shape the beam and form the additively manufactured part.

User defined intensity profile laser beam

The present disclosure relates to a system for repairing a damage site on a surface of an optical material. The system may have an Infrared (IR) laser which generates a laser beam having a predetermined wavelength, with a predetermined beam power, and such that the laser beam is focused to a predetermined full width ('F/W') 1/ediameter spot on the damage site. The IR laser may be controlled to maintain the focused IR laser beam on the damage site for a predetermined exposure period corresponding to a predetermined acceptable level of downstream intensification. The laser beam may heat the damage site to a predetermined peak temperature which causes melting and reflowing of material at the damage site to create a mitigated site.

System and method for laser-based, non-evaporative repair of damage sites in the surfaces of fused silica optics

Techniques for removing material from a substrate are provided. A laser beam is focused at a distance from the surface to be treated. A gas is provided at the focus point. The gas is dissociated using the laser energy to generate gas plasma. The substrate is then brought in contact with the gas plasma to enable material removal.

Laser-induced gas plasma machining

A method for repairing a damage site on a surface of an optical material is disclosed. The method may involve focusing an Infrared (IR) laser beam having a predetermined wavelength, with a predetermined beam power, to a predetermined full width ('F/W') 1/ediameter spot on the damage site. The focused IR laser beam is maintained on the damage site for a predetermined exposure period corresponding to a predetermined acceptable level of downstream intensification. The focused IR laser beam heats the damage site to a predetermined peak temperature, which melts and reflows material at the damage site of the optical material to create a mitigated site.

A method of forming a surface feature extending into a sample includes providing a laser operable to emit an output beam and modulating the output beam to form a pulse train having a plurality of pulses. The method also includes a) directing the pulse train along an optical path intersecting an exposed portion of the sample at a position i and b) focusing a first portion of the plurality of pulses to impinge on the sample at the position i. Each of the plurality of pulses is characterized by a spot size at the sample. The method further includes c) ablating at least a portion of the sample at the position i to form a portion of the surface feature and d) incrementing counter i. The method includes e) repeating steps a) through d) to form the surface feature. The sample is free of a rim surrounding the surface feature.

Method and system for laser-based formation of micro-shapes in surfaces of optical elements

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Manteca, CA, United States of America

Gabriel Mark Guss