Bulk Metallic Glasses XX: Novel Alloys, Processing or Manufacturing Methods
Sponsored by: TMS Structural Materials Division, TMS: Mechanical Behavior of Materials Committee
Program Organizers: Robert Maass, Federal Institute of Materials Research and Testing (BAM); Peter Derlet, Paul Scherrer Institut; Katharine Flores, Washington University in St. Louis; Yonghao Sun, The Chinese Academy of Sciences; Lindsay Greer, University of Cambridge; Peter Liaw, University of Tennessee
Monday 2:00 PM
March 20, 2023
Room: Aqua C
Location: Hilton
Session Chair: Katharine Flores, Washington University in St. Louis
2:00 PM Invited
Thermal Drawing of Bulk Metallic Glasses within Polymer Fibers: Challenges and Opportunities: Fabien Sorin1; 1Ecole Polytechnique Fédérale de Lausanne
Fiber thermal drawing is a well-established technique to fabricate telecommunication optical fibers. In the last twenty years, it has been shown that a variety of materials, including polymeric thermoplastics, elastomers, low melting point metals and optical glasses, could be co-drawn together, enabling the fabrication of multi-material fibers with a wide range of functionalities. Until recently however, no Bulk Metallic Glass (MG) composition have been found to be thermally drawn within polymer matrices. In this presentation, we will first demonstrate that careful materials selections allows for the fabrication of fibers containing nanometer feature size MG of various shapes. Second, we investigate the effect of thermal drawing on the metallic glass properties, and the achievable feature size via, among other techniques in-situ TEM, highlighting an interplay between fluid dynamics and crystallization behavior. Finally, we present various complex fiber-integrated MG architectures with novel applications in smart textiles, bioengineering, and electrochemical sensing.
2:20 PM
Employment of Joule Heating and Simple Mechanical Loading to Stretch Bulk Metallic Glass Rod into Wire: Fiachra Robinson1; Philip Meagher1; David Browne1; 1University College Dublin
Rods of a bulk amorphous Zr-based alloy, diameter 3 mm and 5mm, were manufactured by arc melting and suction casting. The supercooled liquid range and thermal stability were determined by DSC. The vertical rods were heated by applying a voltage across two electrodes along their axis, causing Joule heating. A calibrated infrared camera was used to estimate the rod temperature. When the target temperature was reached the power was cut and an attached weight was released to cause thermoplastic elongation and thinning of the rod. Natural cooling occurred simultaneously, so as the produced wire temperature dropped below the glass transition the strain rate dropped to zero. The process is explained and difficulties in its control are presented, along with suggestions on how to overcome them. It is believed that alloy fragility is an influencing factor. Strain rates achieved so far are insufficient to rejuvenate the BMG.
2:40 PM
Rejuvenation of the Supercooled Liquid State by Straining during Cooling: Ethen Lund1; Rodrigo Mota1; Sungwoo Sohn1; David Browne2; Jan Schroers1; 1Yale University; 2University College Dublin
Rejuvenation and relaxation of bulk metallic glass offer the prospect of tailoring bulk metallic glass structure and, in turn, properties through processing techniques. Here, we investigate methods of accomplishing this, as applied to the supercooled liquid and glass states. Using Zr44Ti11Cu10Ni10Be25 as a model alloy, we demonstrate excitation of the supercooled liquid using an applied strain rate, which can be simultaneously cooled to freeze into a higher energy glass exhibiting improved ductility upon bending. This phenomenon is described by a competition between timescales of the glass, the cooling rate, and the strain rate. Further, elastic processing of the glassy state will be explored to better understand its scalability and effect on structure.
3:00 PM Cancelled
Development and Properties of Marginal Zr-based Bulk Glassy Alloys: Akihisa Inoue1; F.L. Kong1; S.L. Zhu2; A.L. Greer3; 1Josai International University; 2Tianjin University; 3University of Cambridge
BMGs have been produced in the multicomponent alloy systems, where the empirical three component rule is satisfied, and commercialized on a large scale in wide fields. In addition to their ordinary BMGs, we have been recently developing marginal Zr-based BMGs with structural instability to applied strain. That is, the marginal BMGs exhibit the strain-induced structure changes to various composites consisting of glass plus metastable phase such as quasicrystal, approximant crystal, B2, trigonal or hexagonal omega, B22 or hcp phase, accompanying with strain hardening, strain softening and enhanced plasticity. The progress in the development on their novel marginal BMGs is expected to extend the application fields of BMGs. This paper presents our recent data on the deformation-induced changes in the glassy structure, thermal stability and mechanical properties and to investigate the possibility of applying the marginal Zr-based BMGs to a new type of structural material.
3:20 PM Break
3:40 PM
Tuning Microstructure and Enhancing Mechanical Properties of Co-Ni-V and Co-Ni-V-Al Medium Entropy Alloy Thin Films via Deposition Power: Qingping Cao1; 1Zhejiang University
Recently, medium-entropy alloys (MEAs) combining high hardness with excellent ductility have attracted numerous attentions. Here we synthesize a series of Co-Ni-V and Co-Ni-V-Al MEA thin films by magnetron sputtering at room temperature with deposition power from 60 W to 350 W. The film microstructure, morphology, and mechanical properties depended remarkably on atomic fluence, proportional to deposition power. With increasing atomic fluence, the amorphous phase fraction experienced a process of first decreasing and then increasing, and fully amorphous structure was obtained at 300 W for Co-Ni-V-Al and 350 W for Co-Ni-V. Surface diffusion is dominated in low incident atomic energy range, while deposition rate effect is dominant over surface diffusion effect in high incident atomic energy range, resulting in the crossover in phase selection. Our current work could pave a way for a controlled synthesis of high-performance MEA thin films via tuning deposition power.
4:00 PM
Processability of Cu-Ti-based Metallic Glasses via Laser Powder Bed Fusion: Erika Soares Barreto1; Erika Soares Barreto2; Maximilian Frey3; Jan Wegner4; Stefan Kleszczynski4; Ralf Busch3; Lutz Mädler1; Lutz Mädler2; Nils Ellendt1; Nils Ellendt2; 1Leibniz Institute for Materials Engineering—IWT; 2University of Bremen; 3Saarland University; 4University of Duisburg-Essen
Laser powder bed fusion of metals (PBF-LB/M) has been increasingly researched for manufacturing bulk metallic glasses with size and geometry freedom. However, challenges along the processing route towards avoiding crystallization and contamination often compromise the high-quality, amorphous parts production. Here, different purities of Cu-Ti-Zr-Ni glass-formers microalloyed with Si and Si-Sn were gas-atomized and additively manufactured to evaluate the overall processability via the layer-wise fabrication route. Results show good powder flowability, although a propensity for moisture uptake. Increasing oxygen absorption is observed in each processing step, considerably influenced by feedstock purity and gas-atomization. The GFA of powders and PBF-LB/M parts presented negligible differences for the same alloy type, despite varied oxygen levels. The cooling rates of both gas-atomization and the PBF-LB/M process are sufficient for vitrification. Microalloying increases the thermal stability of alloys, yet over an increased brittleness, as seen by an enhanced crack formation.