Event: Dr. Matthews will speak next Wed., Oct. 5th at 4 pm at the Colorado School of Mines, Brown Hall W210
Subject: “Characterization of laser-powder-bed interactions in selective laser melting“
Selective laser melting (SLM) plays an important role in the field of additive manufacturing, enabling the design of complicated geometries that can produce parts rapidly and efficiently. However, despite the significant advances in SLM, the detailed micro- and mesoscale descriptions of the energy coupling, heat flow and mass transport is still not completely available. Here, we directly measure the absorptivity of metal powder layers to characterize energy coupling efficiency and explore melt pool dynamics and motion of ejected particles using high speed imaging. The size of the melt pool and velocity of ejected particles (spatter) from the powder bed is extracted from individual camera frames, revealing new mass transport mechanisms. Finite element simulations were performed to give further insights into the physics of the laser-material interaction and open the pathway to process improvements.
About Dr. Manyalibo (Ibo) J. Matthews
Dr. Manyalibo (Ibo) J. Matthews is principal investigator of multiple research projects involving laser materials processing, high power laser damage and advanced optical diagnostics for in situ process monitoring. Successfully led R&D programs on laser damage mitigation techniques based on IR laser micro-shaping and gas phase additive methods. Prior to LLNL was Member of Technical Staff at Bell Laboratories in Murray Hill NJ from 1998 to 2006, where research centered on material characterization of optical devices using high resolution confocal Raman and fluorescence microscopy, stress-induced birefringence in planar optical devices and noise reduction in advanced broadband access networks. Currently holds 6 U. S. patents and has over 90 peer-reviewed publications.
Bio:
Education and Professional Experience
Ph.D., Physics, Massachusetts Institute of Technology, 1998
B.S., Applied Physics, University of California at Davis, 1993
Dr. Manyalibo (Ibo) J. Matthews
Deputy Group Leader, Materials Science Division
Physical & Life Sciences Directorate Lawrence Livermore National Laboratory
Email: ibo@llnl.gov
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Event: Dr. Wayne King of Lawrence Livermore National Labs will speak at ADAPT/Colorado School of Mines on Nov. 8th from 4 to 5:50 pm in Brown Hall
Subject: “Simulation And Modeling Of The Metal Powder Bed Fusion Additive Manufacturing Process”
Qualification of parts produced using laser powder bed fusion additive manufacturing is broadly recognized as a significant challenge. Physics-based models have been identified as being foundational to qualification of AM metal parts. In this presentation, we discuss a multiscale modeling. This includes a model at the scale of the powder that simulates single track/single-multi layer builds, and provides powder bed and melt pool thermal data. A second model computationally builds a complete part and predicts manufactured properties (residual stress, dimensional accuracy) in 3D. Modeling is underpinned by extensive experimental validation and is tied to experiment through data mining.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This work was funded by the Laboratory Directed Research and Development Program at LLNL under project tracking code 13-SI-002.
Research Details:
About Dr. Wayne King
Dr. Wayne King currently serves as Project Leader of the Accelerated Certification of Additively Manufactured Metals Project at LLNL (). This project is focused on developing physics-based models relating microstructure, properties, and process to performance of materials and includes predictive models for the laser powder bed fusion process. The project also focuses on using integrated in-process sensing, monitoring, and control technologies to accelerate part qualification. He and colleagues were recently published on Simulation And Modeling Of The Metal Powder Bed Fusion Additive Manufacturing Process and Metal powder absorptivity: modeling and experiment.
Bio:
Source: ADAPT
