Dr. Manyalibo “Ibo” Matthews

Division Leader, Materials Science Division

Lawrence Livermore National Laboratory

Topic: "Process Sensing and Control in Metal Additive Manufacturing"

Abstract: High cooling rates and feedstock material based on casting alloys create the conditions for nonequilibrium and often nonideal solidified microstructures during laser powder bed (LPBF) fusion additive manufacturing.  Furthermore, the geometric complexity of metal 3D printed LPBF objects is typically associated with changes in thermal boundary conditions that drives the need for voxel-level thermal process control.  Using a combination of predictive models for the mesoscale melt pool dynamics, thermal history, grain nucleation models and in situ sensing, we show that the net processing conditions can be tailored to produce more optimal material structure and properties.  Furthermore, precise laser energy control as a function of thermal boundary conditions will be shown to also limit macroscale defects in LPBF, further enhancing part-scale properties and performance.  Additional topics in LPBF will be discussed including in situ process monitoring, functionally-graded material processing and micro lattice fabrication.  A brief introduction to Materials Science Division research at LLNL will also be presented. Prepared by LLNL under Contract DE-AC52-07NA27344.

Bio: Dr. Manyalibo (“Ibo”) Matthews leads the Materials Science Division (MSD) at Lawrence Livermore National Laboratory (LLNL), where he oversees an organization of more than 550 staff. The division is organized into 22 scientific capability groups, who together execute research and development projects to support a multitude of LLNL missions. The division’s research includes energetic materials, optical materials, quantum materials, materials for energy applications, ceramics, actinides, and materials for
extreme environments.
Prior to taking on the division leader role in 2021, Matthews served as a group leader in MSD, which is part of LLNL’s Physical and Life Sciences Directorate. He also served as a program group leader in LLNL’s National Ignition Facility and Photon Science Directorate, where he led a team of 40 staff charged with developing new methods in laser materials processing and studying laser-matter interactions in a variety of materials. His research interests include understanding and optimizing metal 3D printing processes, laser materials processing, high-power-laser damage mechanisms, laser-based nanoscale surface modification, vibrational spectroscopy, confocal microscopy, and in situ characterization of transient processes. His scientific work has been featured in more than 175 peer-reviewed publications with >13,000 citations including more than a dozen featured covers, and in three book chapters. His technical contributions have also led to 20 U.S. patents.
Matthews is a Fellow of the American Physical Society, Fellow of the Optical Society of America (Optica) and an alumnus of the Frontiers of Engineering Program, sponsored by the National Academy of Engineering. In 2022 he was recognized as one of Electro Optic’s “Photonics100” innovators. In 2021- 2022, he led an LLNL task force aimed at improving employee development opportunities at the Laboratory, and he continues to invest his time to develop mentorship programs and expand outreach to students at minority-serving institutions, inspiring the next generation to consider careers in science.
Prior to joining LLNL in 2006, he was member of the technical staff at Bell Laboratories in Murray Hill, New Jersey, where he worked on advanced methods for optical materials characterization and led a research team in advanced broadband access networks. Matthews earned his Ph.D. in Physics from the Massachusetts Institute of Technology in experimental condensed matter physics, and his B.S. in Applied Physics from the University of California at Davis. 

Thursday, February 1, 2024

102 BEH

11:00am

Host: Xiayun Zhao