Category: Highlights

Testing Stability of a 3-D Printed Super Alloy under Extremes

Department of Energy, NNSA Center of Excellence CAMCSE researchers have published their latest research in Scientific Reports detailing a high-resolution electron microscopy study on a pressure-treated 3-D printed super alloy known for its unusually high strength and high ductility. https://www.nature.com/articles/s41598-024-67422-x.  

The published study was led by UAB and has participants from the University of Massachusetts-Amherst, the University of California-Irvine, and the University of Notre Dame. The real secret behind superlative mechanical properties of 3-D printed super alloys is the nanostructure arrangement of two different crystalline structures that are present in this material. The crystalline structures involved are simple cubic structures (body-centered cubic and face-centered cubic), but their nano-layer arrangement achieved by 3-D printing resist deformation. Under applied high pressures, body-centered cubic transforms to face-centered cubic, however, stability of nano-layered structure required innovative electron microscopy studies.

PI of CAMCSE Yogesh Vohra says that these results are significant as they utilized state of the art Focused Ion Beam technology to extract few nanometers thick sample from the transformed sample that was compressed in a UAB diamond anvil cell device (Figure below). One nanometer (nm) is one billionth of a meter; for example, human hair diameter is approximately 80,000 nm. The crystalline structure transformation was confirmed by x-ray diffraction using HPCAT facility, Advanced Photon Source, Argonne National Laboratory in Chicago. The electron microscopy was performed on nanometer thick sample to extract the crystal structure and nanostructure morphology induced by application of high pressure. The electron microscopy confirmed the irreversibility of the transformation and quite surprisingly the nano-layer arrangement remained unperturbed even after exposure to extreme pressure of 30 GPa (300 times the pressure at the deepest spot in the ocean) The published work will become part of PhD thesis of graduate student Andrew Pope (lead author on this paper).

Stability of 3-D Printed Super alloy
Ni40Co20Fe10Cr10Al18W2 super alloy sample at the center of the metal gasket after diamond anvil cell compression (A), side (B), and top (C) views of TEM specimen lifted out from the sample using gallium-ion milling method.

Overall goal of CAMCSE is to understand how additively manufactured (3-D printed) material performs under extremes of pressures, temperatures and high velocity impact or shock compression. The fundamental understanding of phase changes and nano structuring in 3-D printed superalloys will help us design better materials

Dr. Melissa Sims Joins the Faculty in the Physics Department at UAB

Dr. Melissa Sims is joining as a tenure-track Assistant Professor in the Department of Physics at the University of Alabama at Birmingham beginning August 2024. Dr. Sims will also be affiliated with DOE NNSA funded Center of Excellence CAMCSE at UAB (https://sites.uab.edu/camcse/). Previously, she was an NSF EAR Postdoctoral Fellow at Johns Hopkins University with a visiting scientist appointment at Lawrence Livermore National Laboratory. Hailing from South Carolina, Dr. Sims earned bachelor’s degrees from the College of Charleston and the University of South Carolina and completed her master’s and doctorate at Stony Brook University.

Dr. Sims’s research focuses on planetary interiors, meteorite impacts, and the behavior of materials undergoing extreme conditions. Her work is dedicated to unraveling the mysteries surrounding solar system formation and planetary evolution and investigates the unique mechanical, thermal, and chemical responses of materials subjected to shock conditions. During her doctorate, Dr. Sims honed her expertise in quasi-static high-pressure techniques, employing in-operando studies to examine the effects of orientation, texture, strain-rate, and pressure on the nucleation and growth of mineral phases commonly found in meteorites.  She has broadened her research to include dynamic experiments using laser and gas-gun platforms, leveraging recent technological advancements and newly available national and international facilities.

Outside of her academic pursuits, Dr. Sims finds joy in playing the violin, riding her horse, and breeding exotic fish.

 

2024 CAMCSE Center Scientific Advisory Committee (CSAC) meeting at UAB

The Center for Additively Manufactured Complex Systems Under Extremes held its annual Center Scientific Advisory Committee Meeting on June 6, 2024, at the University of Alabama at Birmingham.

In attendance were: (front l-r) Drs. Jae-Hwang Lee, Wen Chen, Aaron Catledge, Mr. Anirudh Hari, Dr. Yogesh K. Vohra; (2nd row l-r) Dr. Wenli Bi, Ms. Jadyn Parker, Drs. Christopher Seagle, Vijayi Rangari (3rd row l-r) Drs. Kannassten Appavoo, Kentos Katagiri, James Hamlin, Seth Iwan.