HEMI Seminar: Dr. Thomas Voisin

Please join us for a seminar with Thomas Voisin, deputy group leader for Metallurgy and Advanced Microscopy and staff scientist in the Materials Science Division at Lawrence Livermore National Laboratory (LLNL). The seminar is titled “Microstructures, deformation mechanisms, and corrosion properties of additively manufactured 316L stainless steels.”

The seminar will begin at 10:30 AM on Friday, May 31 in Malone Hall G33/35.

Abstract: At LLNL, laser powder-bed-fusion (L-PBF) has become an additive manufacturing (AM) technique of choice to manufacture complex components, but also to obtain materials with enhanced properties. Rapid thermomechanical cycles during L-PBF retain non-equilibrium microstructures in as-fabricated metallic alloys, most often resulting in improved properties. For L-PBF 316L stainless steels (316LSS), this means breaking the strength/ductility tradeoff and improving resistance to pitting corrosion in seawater.
For mechanical properties, rapid-solidification cellular structures provide an explanation for the significant increase in strength, but much is left to understand concerning the high ductility. We will show that specific dislocation configurations at cell walls trigger mechanical twinning at low stress, which enhances plasticity.
For corrosion, prior studies have shown that the high resistance to pitting in seawater is due to the absence of Mn sulfides. However, pitting mechanisms on as-built surfaces remain largely unknown. We will show that slags that form during LPBF act as pit nucleation sites and the surface oxide on as-built parts contains a thin layer of Mn-rich silicon oxide that formed at high temperature during LPBF, offering exceptional corrosion protection.

This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

Bio: Thomas Voisin is deputy group leader for Metallurgy and Advanced Microscopy and staff scientist in the Materials Science Division at LLNL, leading several projects investigating the relationship between processing, microstructures, and mechanical or corrosion properties of additively manufactured metallic alloys. He is involved in various activities, including fundamental study of plastic deformation of metals and development of new high entropy alloys (refractory and eutectic). More generally, Thomas actively focuses on developing a coherent research group where different in-situ characterization techniques, from atomic to macroscopic scales, work together to accelerate our understanding of metals properties.

HEMI Seminar: Prof. Songbai Ji

Please join us for a seminar with Songbai Ji, a professor of biomedical engineering at Worcester Polytechnic Institute (WPI). The seminar is titled “Sex-specific, multiscale and large-scale modeling of traumatic brain injury.”

The seminar will begin at 11:00 AM on Wednesday, April 24 in Malone Hall G33.

Abstract: Computational models of the brain play a pivotal role in studying the mechanisms of traumatic brain injury and designing mitigation strategies. In this talk, I will share thoughts about how to extend state-of-the-art by combining a global brain injury model with axonal injury models at the microscale through a multiscale modeling approach. The axonal injury models will incorporate significant sex differences in morphology, which are related to the observed sex differences in concussion based on initial findings. Finally, advanced deep learning techniques will be used to dramatically reduce the simulation cost form hours to under a second. This will enable large-scale modeling of head impacts to conduct population-based injury studies, as opposed to being limited to a single head impact for a specific individual. With wearable head impact sensors more widely adopted, these tools could pave the way for improved onsite injury detection during practices and games for contact sports players and other practical applications, such as better design of protective headgears.

Bio: Dr. Songbai Ji is a Professor of Biomedical Engineering at the Worcester Polytechnic Institute (WPI), Massachusetts, a Sigma Xi Outstanding Senior Researcher. He has more than 20 years’ experience in impact biomechanics of the brain with more than 100 referred journal papers and numerous conference proceeding papers published. His work in this area is best known for the Worcester Head Injury Model (WHIM), which has been continuously funded by the NIH, NSF, and industry for its development. He serves as an associate editor for a number of journals, including Journal of Biomechanical Engineering, Frontier, etc.. Recently, he co-led an international committee for a consensus white paper on “best practices” of brain impact modeling for sports-related concussion (Ji et al., ABME 2022).

HEMI Seminar: Dr. Tian Xie

Please join us for a seminar with Dr. Tian Xie, a senior researcher and project lead at Microsoft Research AI4Science. The seminar is titled “MatterGen: a generative model for inorganic materials design.”

The seminar will begin at 2:30 PM on Friday, Feb. 23 in Gillman Hall 50.

This seminar will also be accessible virtually. Connection information will be distributed the morning of the seminar via email. Those interested in attending who are not on HEMI’s email list can reach out to Sarah Preis at [email protected] for connection information.

Bio: Tian Xie is a senior researcher and project lead at Microsoft Research AI4Science. He leads a team of researchers, engineers, and program manager to develop the next generation machine learning models for materials discovery. Before joining Microsoft, he was a postdoc in the Computer Science and Artificial Intelligence Laboratory (CSAIL) at MIT from 2020 to 2022, co-advised by Tommi Jaakkola and Regina Barzilay. He got his PhD in Materials Science and Engineering at MIT in 2020, advised by Jeffrey C. Grossman. Tian is most known for his research in graph representation learning and generative models for materials, including widely used models like CGCNN and CDVAE.

HEMI Seminar: Prof. Moataz Attallah

Please join us for a seminar with Prof. Moataz Attallah of the University of Birmingham. The seminar is titled “Accelerating Materials and Process Development in Additive Manufacturing.”

The seminar will begin at 3:00 PM on Monday, Dec. 4 in Malone Hall 137.

This seminar will also be accessible via Zoom. Connection information will be distributed the morning of the seminar via email. Those interested in attending who are not on HEMI’s email list can reach out to Sarah Preis at [email protected] for connection information.

Bio: Professor Moataz Attallah holds a chair in advanced materials processing at the School of Metallurgy and Materials University of Birmingham, where he leads the Advanced Materials & Processing Lab (AMPLab). His research focuses on metallic materials processing, with an emphasis on laser-based additive manufacturing, AM post-processing strategies, and novel applications of metal AM in the aerospace, nuclear, defence, motor racing, space, and telecommunications sectors. He sits on the advisory board and provides consultancy to companies and universities in Europe, North America, the Middle East and Asia. He co-authored over 200 scientific reports and 3 book chapters, as well as being a co-inventor on 5 granted patents.

HEMI Seminar: Richard A. Regueiro

Please join us for a seminar with Prof. Richard Regueiro, University of Colorado Boulder, titled “Overview of Center for micromorphic multiphysics porous and particulate materials simulations within exascale computing workflows.”

The seminar will begin at 11:00 AM on Friday, Nov. 10 in Malone Hall 137.

Bio: Professor Richard Regueiro received his PhD in Civil and Environmental Engineering at Stanford University in 1998. He then became a member of the technical staff at Sandia National Laboratories, California, from 1998 to 2005, at which time he began his academic career in the Department of Civil, Environmental, and Architectural Engineering at the University of Colorado Boulder. His research focuses on computational multiscale multiphysics materials modeling for simulating inelastic deformation and failure in heterogeneous porous media, including saturated and partially saturated soils and rock, unbonded particulate materials (e.g. sand, gravel, metallic powders), bonded particulate materials (e.g., sandstone, asphalt, concrete, explosive materials), soft biological tissues (e.g., ocular lens tissue, lung parenchyma, vertebral disk), and thin deformable porous materials and membranes, for instance. Scales of interest range from the microstructural and ultrastructural to the continuum. He is currently Principal Investigator (PI) for an NNSA Advanced Simulation and Computing (ASC) Predictive Science Academic Alliance Program (PSAAP) project, “Center for Micromorphic Multiphysics Porous and Particulate Materials Simulations within Exascale Computing Workflows.”

HEMI Seminar: Prof. Anindya Deb

Please join us for a seminar with Prof. Anindya Deb from the Centre for Product Design and Manufacturing at the Indian Institute of Science, Bangalore. The seminar is titled “Explorations in CAE (Computer-Aided Engineering) for Vehicle Crash Safety Design.”

The seminar will begin at 11:00 AM on Tuesday, Nov. 14 in Malone Hall 137.

Bio: Dr. Anindya Deb is currently a Professor (Higher Administrative Grade) at the Centre for Product Design and Manufacturing (CPDM), Indian Institute of Science (IISc), Bangalore. He is also an Associate Faculty Member at the Interdisciplinary Centre for Energy Research, IISc. He served as a Chairman of CPDM during the period 2009-2014. He previously obtained his (a) PhD from the State University of New York at Buffalo, Amherst, NY, USA, (b) ME from the Memorial University of Newfoundland, St. John’s , Canada, and (c) BE from Jadavpur University, Kolkata, India. In CPDM, IISc, he established CAR (Creative Automotive Research) and Impact Safety Engineering Laboratory (CARISEL). Prior to joining IISc, he had worked with Ford Motor Company (Dearborn, Michigan), SDRC (Milford, Ohio), Caddtech Productivity (Liverpool, New York) and Tata Motors (Jamshedpur, Jharkhand, India). He also held a part-time position of Adjunct Lecturer with the University of Michigan at Dearborn, MI, USA. In IISc, he has supervised a total of around 50 PhD, MTech and MDes students in their theses and projects. He has published substantively (about 200 papers) in international journals and conference proceedings, and obtained 5 patents and a design registration. He has received several awards in industry and academia, and is a Fellow of the Indian National Academy of Engineering (INAE) as well as SAE (Society of Automotive Engineers, USA). He has also been the Principal Investigator for a number of government- and industry-funded research projects. His areas of research include: CAE (Computer-Aided Engineering) in design, design of automotive systems, vehicle crash safety design, impact testing and simulation, design and prototyping of lightweight electric vehicles, fiber-reinforced composites, MDO (Multi-Disciplinary Design Optimization), AI/ML in design, human body modeling, and biomechanical assessment of medical implants/fixations.

HEMI/MICA 2018 Artist in Residence Introduction: Prof. Jenna Frye

Martin Gardner (October 21, 1914 – May 22, 2010) was an American popular mathematics and science writer who wrote about math puzzles and intellectual recreations in Scientific American for a quarter-century. Despite his lack of formal mathematical training, his column “Mathematical Games” has had a huge impact on the way people view math and engage with mathematical concepts recreationally. Every year on his birthday, mathematicians, scientists, artists and puzzle enthusiasts around the globe gather to honor Gardner’s work with math puzzles, logic puzzles, hexaflexagons and Möbius strips, magic and card tricks and visual paradoxes.

Join Prof. Jenna Frye, our 2018 HEMI/MICA Artist/Designer in Residence, to celebrate Gardner’s legacy by making your own hexaflagons and solving playful puzzles. Feel free to bring a magic trick, puzzle, optical illusion or recreational mathematics problem to share!

HEMI Seminar: Prof. Katsunori Hanamura

A sustainable conversion systems through nano/micro scaled phenomena

In the lecture I will briefly introduce our ongoing research projects relating to electromagnetic, electrochemical, fluid-dynamic and catalytic phenomena for enhancement of transport of energy and molecule using nano-scaled technologies which can be scaled up for macroscopic enhancement of high efficiency energy conversion.

1. Generation of electricity by radiation spectrally-controlled using micro-structured surfaces

We are conducting a research on an electricity generation system using a GaSb semiconductor thermophotovolaic cell. In this case, since the GaSb cell has an active range from visible to 1.8 microns wavelength, spectral control should be required in both cases of far- and near-field radiation. In the case of far-field radiation, microcavity structure is useful from a wave guide theory for metals, while in the case of near-field radiation, a pillar-array structure is useful from an interference and resonance of Surface Plasmon Polariton (SPP).

2. A high power density Solid Oxide Fuel Cell using an anode incorporating Proton Conductor

We are conducting a research on an integrated system between a biomass gasification catalyst reformer with a hydrogen separation film and a solid oxide fuel cell with an anode incorporating proton conductor. The SOFC produces electricity with thermal energy under the condition of an operating temperature around 1000K, while the hydrogen will be produced though endothermic reaction under the condition of thermodynamically-required temperature around 1000K. As a result, an internal reforming system in the SOFC will provide the highest total conversion efficiency. In the case of biomass gasification, only the hydrogen produced in the porous Ni catalyst reformer goes though the separation film made of a thin silica glass and then will be supplied for the SOFC. The reduction of hydrogen concentration leads to advanced progress of reaction to produce hydrogen. On the other hand, in the case of SOFC, a new anode incorporating proton conductor was proposed.

The BCY (Barium Cerium Yttrium oxide) plays an important role of hydrogen adsorption and excellent supply the adsorbed hydrogen into the three phase boundary (TPB). As a result, using the proton conductor, the reaction overpotential (reaction resistnce) was reduced to an almost half of that of the conventional anode SOFC.

3. Development of Diesel Particulate Membrane Filter (DPMF) for zero emission vehicles

We are conducting a research on a Diesel Particulate Membrane Filter (DPMF) and the conventional DPF. The soot filtration efficiency will be almost 100% after soot cake was established on the DPF wall surface. As a result, a membrane made of nano-sized SiC-particles will become an excellent filter even for nano-scaled diesel particulates. In addition, a thin oxide layer on the surface of SiC nanoparticle plays an important role on oxygen adsorption. The adsorbed oxygen was reacted with soot under the condition of a lower temperature than that for the conventional DPF. Moreover, including a single-nano-scaled Platinum particle in the oxide layer, the oxidation temperature becomes lower.

Using the DPMF, a zero emission vehicle will be achieved in near future.


Katsunori Hanamura is the professor of School of Engineering, Tokyo Institute of Technology, Japan. He received his Ph. D from Tokyo Institute of Technology in 1991. He started his career as the research associate in Department of Mechanical Engineering, Tokyo Institute of Technology in 1984 and was promoted as the full professor in 2003. Prof. Hanamura’s research interests are primarily focused on thermal engineering, near-field radiation transfer, SOFC and biomass gasification. He is the leader of JST national program on phase interface science for highly efficient energy utilization. (http://www.mep.titech.ac.jp/~TANSO/hanamura/e_framepage/index-j.htm)

HEMI Seminar: Projects in Additive Manufacturing and Charged Polymers at the Army Research Laboratory

Projects in Additive Manufacturing and Charged Polymers at ARL

Additive Manufacturing (AM) processes are revolutionizing the on-demand capabilities of current front-line missions for the modern soldier, allowing unprecedented levels of manufacturing versatility and multi-functionality as needed. As the technology continues to mature, new materials and methods for evaluating AM parts will be required. In this seminar, a variety of important topics related to polymer additive manufacturing at the US Army Research Laboratory are discussed, including applications in the areas of: recycling of front-line battlefield polymer waste for on-demand AM, fabrication of novel filaments for AM processes, and construction of nanocomposites using AM. Techniques for evaluating mechanical performance of AM polymers are also discussed, including topics in the areas of interfacial mechanical behavior and fracture properties.

Nikki Zander, Dan Cole, Kevin Hart, and Frank Gardea from the Army Research Lab will be joining us at the Johns Hopkins University Homewood Campus. Seminar will be held at 11 AM in Malone Hall, G 33/35.