Bulk Metallic Glasses XVIII: Alloy Development and Application I
Sponsored by: TMS Structural Materials Division, TMS: Mechanical Behavior of Materials Committee
Program Organizers: Peter Liaw, University of Tennessee; Yanfei Gao, University of Tennessee-Knoxville; Hahn Choo, University of Tennessee; Yunfeng Shi, Rensselaer Polytechnic Institute; Robert Maass, Federal Institute of Materials Research and Testing (BAM); Xie Xie, FCA US LLC; Gongyao Wang, Globus Medical
Tuesday 8:30 AM
March 16, 2021
Room: RM 7
Location: TMS2021 Virtual
Session Chair: Peter Liaw, The University of Tennesee; Jinn Chu, National Taiwan University of Science and Technology
8:30 AM Invited
Overview on Additive Manufacturing Techniques for Bulk Metallic Glasses: Douglas Hofmann1; Punnathat Bordeenithikasem1; Samad Firdosy1; Andre Pate1; Daniel East2; 1NASA JPL/Caltech; 2CSIRO
Additive manufacturing (AM) has emerged as a unique method for producing highly specialized metal alloys and composites. The high cooling rates afforded by AM are particularly useful in the creation of bulk metallic glasses (BMGs), BMG composites, and BMG/crystalline alloys. This talk will focus on some of the AM techniques that have been used on BMGs, including laser foil printing, ultrasonic additive manufacturing, directed energy deposition, laser powder bed printing, fused filament fabrication and thermal spray additive manufacturing. Special attention will be paid to feedstock material, porosity, and thermal history of the printed BMG and how those affect properties.
8:55 AM
Demisability of Bulk Metallic Glasses for Potential Satellite Applications: Punnathat Bordeenithikasem1; Scott Roberts1; Douglas Hofmann1; J. Martin Ratliff1; Benton Greene2; John Bacon2; Sungwoo Sohn3; Jan Schroers3; 1NASA Jet Propulsion Laboratory; 2NASA Johnson Space Center; 3Yale University
Bulk metallic glasses (BMGs) have garnered interest for utilization as spacecraft components due to their attractive mechanical properties and versatility in fabrication. To mitigate the generation of space debris, at the end of mission, low Earth-orbiting satellites reenter the atmosphere. The number of satellite components that reach the ground must be limited to ensure public safety. BMGs, being designed near deep eutectics, possess lower melting points in comparison to other alloys of similar strength, and therefore more reliably ablate during atmospheric entry. Experiments using inductively coupled plasma with Ar/air mixture were used to simulate reentry conditions and elucidate the demisability of BMGs compared to aluminum and titanium alloys.
9:15 AM
Nanomolding Far and Close to Equilibrium: Naijia Liu1; Guannan Liu1; Arindam Raj1; Sungwoo Sohn1; Jan Schroers1; 1Yale University
Tremendous effort has been taken for nanofabrication of metals as they exhibit desirable functional properties. However, existed approaches are typically limited in some critical aspects such as material choice, geometry, and scalability. As a versatile and widely used method, nanomolding is realized for soft materials including polymers, gels, and glasses, but not for crystalline metals that remain hard in crystalline state. Recently, we discovered that nanomolding is possible with crystalline metals and results into single crystal nanowires by atomic diffusion down a pressure gradient. Most effective at ~0.5 Tm, such thermomechanical-nanomolding (TMNM) results in very high aspect ratio up to 1000 and nanowires down to 5 nm in diameter. We will discuss the underlying mechanism resulting into the formation of single crystals, the observed change in composition in solid solutions and precise maintenance in composition in intermetallics, and TMNM as a versatile tool for nanofabrication of functional intermetallics and heterostructures.