Article
Materials Science, Multidisciplinary
B. G. F. Eggert, E. K. Delczeg-Czirjak, B. C. Hauback, C. Frommen
Summary: FeCoNi, V0.85FeCoNi, FeCoNiCu1.15, and V0.85FeCoNiCu1.15 alloys were synthesized and analyzed to evaluate their magnetic properties and magnetocaloric effect. The presence of Cu and V dilutes the magnetic properties and couples antiferromagnetically to Fe, Co, and Ni. The microstructure analysis reveals a lack of solubility between V and Cu with FeCoNi, resulting in reduced concentrations of V and Cu in the main solid solution of the alloy. The use of V and Cu has shown potential for tuning the magnetocaloric effect in FeCoNi-based high entropy alloys.
MATERIALS TODAY PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Mark Fedorov, Jan S. Wrobel, Witold Chrominski, Grzegorz Cieslak, Magdalena Plocinska, Krzysztof J. Kurzydlowski, Duc Nguyen-Manh
Summary: The relative phase stability of fcc and bcc Cr-Fe-Mn-Ni alloys was studied using density functional theory, cluster expansion (CE), and Monte Carlo (MC) simulations. The CE models enabled the calculation of Gibbs free energies of formation for different compositions, and the MC simulations provided insights into the stability of these alloys at different temperatures. The results obtained were in line with experimental data and helped identify the alloys that are predicted to have a single fcc phase over a wide temperature range.
Article
Materials Science, Multidisciplinary
Qigui Yang, Par Olsson
Summary: Understanding the formation and evolution of Cu precipitates in Fe-based alloys is crucial for their hardening and embrittlement effects. This study presents a first-principles investigation of positron annihilation in Fe-Cu systems, accurately predicting the characteristics of various homogeneous and heterogeneous Cu precipitates. The theoretical results show excellent agreement with experimental data, enabling clear distinction of different Cu precipitate types and reasonable estimation of their sizes. This work enhances the understanding of early-stage Cu precipitation in Fe matrix.
Article
Nanoscience & Nanotechnology
Kang Du, Yang Zhang, Guangda Zhao, Tao Huang, Liyuan Liu, Junpeng Li, Xiyu Wang, Zhongwu Zhang
Summary: This paper systematically investigated the evolution of microstructure in Fe-Ni-Co-Al polycrystalline alloys and its effects on mechanical properties. The results revealed that the migration of grain boundaries in different processes is driven by different factors, which impacts the grain orientation and precipitate formation. In the process of directional recrystallization, grains with specific orientations grow in the grain boundary region and form the dominant orientation, while grains with lower migration rate form the minor orientation. The alloy produced through directional recrystallization exhibited good recoverable strain and superelastic strain, while the alloy produced through solid solution treatment showed no evident superelastic behavior.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Nanoscience & Nanotechnology
N. J. Aerne, D. J. Sprouster, J. D. Tucker
Summary: The precipitation of new phases during long-term service at elevated temperatures is a concern for the thermal stability of engineering alloys. In this study, the formation and evolution of Ni2Cr precipitation in Ni-Cr-Fe model alloys with different Fe contents and Ni/Cr atomic ratios were quantified. The impact of precipitate size on the mechanical properties as a function of Fe content was also investigated. The results showed that Ni2Cr formation was observed in certain Fe-containing alloys, and the face-centered cubic matrix lattice contraction and Vickers hardness were correlated with the Ni2Cr formation. A precipitation hardening model was developed based on critical resolved shear stress, showing a clear link between Ni2Cr precipitate size and hardness.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Christian Timmer, Wolfgang Tillmann, Lukas Wojarski, Manuel Pinho Ferreira
Summary: In response to the increasing demand and carcinogenic effect of cobalt, alternative metal matrixes without cobalt are developed for hot-pressed diamond tools. Through experimentation, Cr5Cu20Fe25Mn25Ni25 alloy is identified as a promising cobalt-free metal matrix material.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Vadym Drozd, Mohammad Asadikiya, Songge Yang, Yu Zhong
Summary: In this study, the properties of fcc random solid solutions in the Fe-Ni binary system were investigated using density functional theory calculations, showing that the 16-atom SQS model provides an effective approach for predicting mixing energy of the alloy. However, larger supercells are needed for calculating mechanical properties. Excellent agreement between experimental and calculated elastic properties was found in the fcc region of the Fe-Ni system.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Marlena Ostrowska, Paola Riani, Brandon Bocklund, Zi-Kui Liu, Gabriele Cacciamani
Summary: In this study, the computational thermodynamics of Al-Co-Cr-Fe-Ni alloys were modeled using the CALPHAD approach based on literature data and key experimental results. A thermodynamic database for Al-Co-Cr-Fe-Ni was developed, incorporating assessments of binary and ternary subsystems and the addition of quaternary interaction parameters. The computed phase equilibria in the quinary system showed good agreement with experimental data.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Xuelian Xiao, Keke Chang, Kai Xu, Ming Lou, Liping Wang, Qunji Xue
Summary: In this study, phase diagrams and Pourbaix diagrams were simultaneously constructed using the CALPHAD method and a well-constructed thermodynamic database. These diagrams accurately predicted the phase evolution and corrosion behavior of alloys in the immune and passive regions, providing significant implications for corrosion studies of multi-component alloys.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Kanghyun Park, Byungchan Cho, Soon Jik Hong, Ka Ram Lim, Chanho Lee, Gian Song
Summary: We designed and developed a novel ferritic alloy that exhibits excellent high-temperature yield strength enhancement through coherent hierarchical precipitates. The composition of the alloy was tailored by adding Vanadium to a Fe-Cr-Ni-Al alloy to control the size and volume fractions of coherent B2-NiAl precipitates. Experimental and theoretical approaches were used to examine the evolutions of microstructures, mechanical properties, and strengthening mechanisms at 973 K. It was found that the addition of Vanadium reduces the lattice misfit and precipitate size, and a hierarchical structure within the precipitate plays a vital role in enhancing the yield strength at 973 K.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Jie Pan, Zixie Wang, Qiliang Mei, Mengli Li, Jing Gao, Jun Li, Mengqi Wang, Hui Li, Zhaoyu Wu, Xueshan Xiao
Summary: A series of FeCrNi alloys with different Ni content incorporated with Gd were designed and fabricated. Gadolinium-rich precipitates were identified through various characterization techniques. The type of precipitates transformed from M3Gd to M5Gd intermetallic compound when the Ni content reached 30 wt.%. The melting temperature of both M3Gd and M5Gd phases improved with increasing Ni content. The alloys with more than 30 wt.% Ni content also showed excellent shielding properties, warranting further investigation.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Patrick L. J. Conway, David Golay, Lori Bassman, Michael Ferry, Kevin J. Laws
Summary: This study examines the potential of thermodynamic modeling in assessing phase stability in high entropy alloys, compares it with CALPHAD calculations, and demonstrates the value of new models in predicting and designing phase constitution in future high-performance alloys.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
H. T. Vo, K. Dang, F. Teng, M. Schneider, B. P. Eftink, S. A. Maloy, J. D. Tucker, L. Capolungo, P. Hosemann
Summary: Nickel-based alloys are widely used in extreme environments due to their exceptional mechanical properties, which are derived from the addition of long-range ordered precipitates introduced by thermal aging. Pt2Mo-structured precipitates in these alloys enable room-temperature deformation twinning in addition to slip, increasing strain hardenability. However, factors influencing the activation of twinning versus slip in this class of alloys have not been thoroughly explored.
MATERIALS & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Rostyslav Nizinkovskyi, Thorsten Halle, Manja Krueger
Summary: This study develops a phase-field model to investigate the formation of elongated morphology of fcc-Cu precipitates in the bcc-Fe matrix. The results suggest that the influence of elastic properties and applied stress on the morphology formation is minor. Additionally, a bifurcation diagram of the interaction of two precipitates is constructed, revealing the role of elasticity in enhancing the kinetics of the reaction.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Chemistry, Physical
Zhicheng Zheng, Dan Wu, Long Chen, Shuo Chen, Hao Wan, Gen Chen, Ning Zhang, Xiaohe Liu, Renzhi Ma
Summary: Ni-based hydroxides are excellent electrocatalysts for alkaline urea oxidation reaction (UOR), and appropriate Co element doping greatly improves the UOR performance. Only part of NiCo hydroxides are converted to NiCo oxyhydroxides, which drive the subsequent UOR. The UOR on NiCo oxyhydroxides competes with the redox reaction of NiCo hydroxides.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2024)
Article
Nanoscience & Nanotechnology
Boopathy Kombaiah, Yufan Zhou, Ke Jin, Anus Manzoor, Jonathan D. Poplawsky, Jeffery A. Aguiar, Hongbin Bei, Dilpuneet S. Aidhy, Philip D. Edmondson, Yanwen Zhang
Summary: High-entropy alloys (HEAs) exhibit good radiation tolerance, but some HEAs suffer from considerable void swelling at high radiation damage levels, limiting their application in advanced nuclear reactor concepts. By introducing Cu-rich nanoprecipitates and corresponding coherent interfaces in the HEA matrix, the void swelling resistance of the alloy can be significantly improved. Experiments and simulations demonstrate that the high-density interfaces of the nanoprecipitates facilitate the effective recombination of radiation-produced vacancies and interstitials.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Shuying Chen, Jingbo Qiao, Haoyan Diao, Tengfei Yang, Jonathan Poplawsky, Weidong Li, Fanchao Meng, Yang Tong, Liang Jiang, Peter K. Liaw, Yanfei Gao
Summary: Improving creep resistance is often achieved by optimizing alloy design to create strong solid-solution strengthening and/or coherent precipitates for dislocation blockage. High-entropy alloys (HEAs), which are single-phase solid-solutions, exhibit creep properties comparable to precipitate-strengthened ferritic alloys. However, many HEAs develop incoherent second phases during long-term annealing, reducing their lifetime and limiting their use at high temperatures. This study demonstrates the exceptional creep resistance of a non-equiatomic Al0.3CoCrFeNi HEA, which has a much lower creep strain rate compared to the Cantor alloy and its subsets. The research reveals that the suppression of B2 precipitate phase during the early stage of creep deformation and the emergence of metastable and coherent L1(2) precipitates significantly contribute to creep strengthening.
Article
Nanoscience & Nanotechnology
Zezhou Li, Justin Y. Cheng, Jonathan D. Poplawsky, Shuozhi Xu, Jon K. Baldwin, Irene J. Beyerlein, Nathan A. Mara
Summary: In this study, the local chemistry of three-dimensional (3D) interfaces in Cu/Nb nanocomposites was characterized using atom probe tomography (APT). The analysis revealed chemical heterogeneities along all spatial dimensions in the 3D interfaces, established the length scale and morphology of these features. It was found that the heterogeneities in 3D interfaces form through surface diffusion during physical vapor deposition (PVD), indicating that deposition parameters can be used to control interface structure and explore processing-structure-property relationships in interface-dominated nanocomposites.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
Sophie H. van Vreeswijk, Luke A. Parker, J. J. Erik Maris, Jonathan D. Poplawsky, Bert M. Weckhuysen
Summary: The coking behavior of zeolite catalyst materials was studied using atom probe tomography (APT) and confocal fluorescence microscopy. APT revealed the link between framework and coke distributions, while fluorescence microscopy showed the effect of crystal morphology on coke distribution. A short length-scale affinity between carbon and aluminum atoms was also observed.
Article
Chemistry, Physical
Kevin D. Sisco, Alex Plotkowski, Ying Yang, Larry Allard, Chris Fancher, Claudia Rawn, Jonathan D. Poplawsky, Ryan Dehoff, S. S. Babu
Summary: Heat treatment of additively manufactured Al-Ce based multicomponent alloys leads to complex micro-structure evolution. The study explores the phase transformation theories involving nucleation from a heterogeneous multi-phase microstructure typical to that of additively manufactured samples. Different solidification microstructures were obtained due to spatial and temporal variations of thermal gradients (G) and liquid-solid interface velocities (R) within a given melt pool. The phase transformation pathways are rationalized based on the role of driving force on the nucleation of different phases at the interface of aluminum and the non-equilibrium intermetallic phases.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Nanoscience & Nanotechnology
Matthew Luebbe, Jiaqi Duan, Fan Zhang, Jonathan Poplawsky, Hans Pommeranke, Maalavan Arivu, Andrew Hoffman, Mario Buchely, Haiming Wen
Summary: Recent studies have shown that precipitation-hardened high-entropy alloys (HEAs) exhibit high strength and thermal stability, making them promising for high-temperature applications like nuclear reactors. However, many HEAs contain unsuitable cobalt (Co) due to its long-term activation issue and high cost. This study developed a Co-free (Fe0.3Ni0.3Mn0.3Cr0.1)(88)Ti4Al8 HEA, which exhibited a complex four-phase structure and a compressive strength of 2151 MPa. B2 and chi phases provided significant strengthening effects, while gamma ' nanoparticles also contributed to the alloy's strength. This research lays the foundation for further development of Co-free HEAs with improved ductility.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Evan B. Raeker, Kira M. Pusch, Stephane A. J. Forsik, Ning Zhou, Austin D. Dicus, Qing-Qiang Ren, Jonathan D. Poplawsky, Michael M. Kirka, Tresa M. Pollock
Summary: The cracking behavior of a CoNi-base superalloy fabricated via laser powder bed fusion was studied in relation to carbon and boron content. It was found that increasing the boron content led to severe cracking, while compositions with higher carbon and lower boron showed minimal cracking. Scan electron microscopy showed evidence of solidification cracking mode, and differential thermal analysis revealed decreased incipient melting temperature for high-boron composition. The simulations of solidification cracking susceptibility and atom probe tomography measurements provided valuable insights for designing new superalloys for additive manufacturing.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Chemistry, Physical
Deng-Bing Li, Sabin Neupane, Sandip S. Bista, Chuanxiao Xiao, Abasi Abudulimu, Manoj K. Jamarkattel, Adam B. Phillips, Michael J. Heben, Jonathan D. Poplawsky, David A. Cullen, Chun-Sheng Jiang, Randall J. Ellingson, Yanfa Yan
Summary: Our previous work has shown that the formation of a penternary cadmium chalcogenide Cd(O,S,Se,Te) region can reduce front interface recombination in Cd(Se,Te)-based thin-film solar cells. In this work, we demonstrate that managing oxygen during device fabrication is crucial for forming this region. Improper oxygen management leads to low device performance due to the formation of a photoinactive Cd(S,Se) region and reduced absorber quality. Additionally, we investigate carrier transport and collection properties to understand the mechanisms resulting in improved efficiencies approaching 20%.
ACS ENERGY LETTERS
(2023)
Article
Engineering, Manufacturing
Sumit Bahl, Alex Plotkowski, Thomas R. Watkins, Richard A. Michi, Benjamin Stump, Donovan N. Leonard, Jonathan D. Poplawsky, Ryan Dehoff, Amit Shyam
Summary: Additive manufacturing (AM) allows for the printing of structures with site-specific properties. In this study, a simple approach utilizing eutectic solidification characteristics is demonstrated to achieve site-specific properties in an Al-Cu-Ce-Zr alloy using laser powder bed fusion AM. The yield strength of the alloy can be tuned by adjusting the laser scan speed and hatch spacing, with faster speeds resulting in finer eutectic spacing and higher strength. The relationship between scan speed, eutectic spacing, and strength is successfully applied to print a complex pattern of site-specific hardness in the alloy, showcasing the potential of using AM for creating site-specific properties and anisotropy in alloys.
ADDITIVE MANUFACTURING
(2023)
Article
Materials Science, Multidisciplinary
R. Pillai, Q. Q. Ren, C. J. Stephens, Yi-Feng Su, M. J. Lance, J. Poplawsky, D. Schlagel, T. Lograsso, Y. Yamamoto, M. P. Brady
Summary: This study aims to quantitatively describe the role of Ni in promoting or disrupting the formation of protective Al2O3 scale on AFA alloys. Ternary Fe-Al-xNi model alloys with different Ni contents were isothermally exposed to evaluate the impact of Ni on internal oxidation behavior. The results showed that increasing Ni contents had no effect on the internal oxidation behavior, while highlighting the challenges in developing reliable models for computation-assisted design of these alloys.
Article
Materials Science, Multidisciplinary
Zachary Harris, Elena Garlea, Tasha Boyd, Lisa DeBeer-Schmitt, Kenneth Littrell, Sean Agnew
Summary: The effect of microstructure on the internal hydriding behavior of cast and rolled uranium containing varying hydrogen concentrations was evaluated through small angle neutron scattering (SANS). The size of uranium hydride (UH3) precipitates in cast uranium was weakly affected by increasing hydrogen content, while the phase fraction of UH3 showed a strong dependence on hydrogen content. Rolled uranium exhibited a significantly reduced UH3 particle size distribution compared to cast uranium with the same hydrogen content, hypothesized to be driven by increased hydrogen trapping at grain boundaries, which is supported by theoretical calculations.
Article
Chemistry, Multidisciplinary
Florian Zand, Suzanne J. T. Hangx, Christopher J. Spiers, Peter J. van den Brink, James Burns, Matthew G. Boebinger, Jonathan D. Poplawsky, Matteo Monai, Bert M. Weckhuysen
Summary: Understanding and controlling the structure and composition of nanoparticles in supported metal catalysts are crucial for improving chemical processes. Atom probe tomography (APT) is a powerful tool for three-dimensional chemical imaging of materials with nanometer resolution. However, APT has not been used for mesoporous oxide-supported metal catalysts due to sample fracture. In this study, we developed a high-pressure resin impregnation strategy to overcome this issue and successfully applied APT to high-porous supported Pd-Ni catalyst materials active in CO2 hydrogenation. Our results demonstrate the capability of APT to quantitatively assess the size, composition, and metal distribution of nanoparticles in industrial catalysts.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Nanoscience & Nanotechnology
Andrew M. Alvarado, Chanho Lee, Jan S. Wrobel, Damian Sobieraj, Duc Nguyen-Manh, Jonathan D. Poplawsky, Saryu Jindal Fensin, Enrique Martinez, Osman El-Atwani
Summary: Short-range order (SRO) affects the mechanical response of multicomponent concentrated alloys, making it crucial to understand how composition modifies chemical ordering for optimal material design. We propose a methodology to predict SRO and thermodynamic properties in chemically complex systems, and apply it to the WTaCrVHf quinary alloy. We observe significant modification of SRO at intermediate to low temperatures with the addition of Hf, consistent with experimental observations.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Analytical
Michael Titze, Jonathan D. Poplawsky, Silvan Kretschmer, Arkady V. Krasheninnikov, Barney L. Doyle, Edward S. Bielejec, Gerhard Hobler, Alex Belianinov
Summary: Ion implantation is a crucial capability in the semiconductor industry. This study demonstrates a method for low-energy gold implantation and emphasizes the importance of model details in simulations.
Review
Materials Science, Multidisciplinary
Ishtiaque Karim Robin, Tim Graning, Ying Yang, Syeda Bushra Haider, Eric Andrew Lass, Yutai Katoh, Steven John Zinkle
Summary: This study investigates solid-state bonding techniques, with a focus on diffusion bonding, as an effective method for establishing engineering bonds. Diffusion bonding offers a lower temperature process and can handle materials with large differences in melting temperature. The insights from this research can be applied to various industries, enabling advanced and efficient design.
