Article
Engineering, Mechanical
Jiyao Zhang, Yuanlie Yu, Junlei Tang, Yingying Wang, Honggang Sun, Kaikai Song, Jianhong Gong, Pingping Liu, Xiaoming Liu, Lina Hu, Parthiban Ramasamy, Juergen Eckert
Summary: The influence of high-carbon addition on the microstructure, hardness, and wear behavior of CoCrNi alloy was investigated. It was found that the addition of carbon resulted in the formation of carbide particles, enhancing the hardness and improving the wear resistance. Fracture and detachment of hard carbides during friction introduced additional abrasive particles, transitioning the wear mechanism from adhesive-dominated to abrasive-dominated.
Review
Materials Science, Multidisciplinary
B. Cantor
Summary: Multicomponent high-entropy Cantor alloys, discovered in the late 1970s, occupy a vast region of multi-component phase space and exhibit excellent mechanical properties due to high configurational entropy. The complexity of local atomic configurations and associated lattice strains in these alloys contributes to their unique characteristics and potential for further enhancement and optimization.
PROGRESS IN MATERIALS SCIENCE
(2021)
Article
Metallurgy & Metallurgical Engineering
Rui Li, Lei Guo, Yu Liu, Qingsong Xu, Qing Peng
Summary: With their excellent irradiation resistance due to chemical complexity, high entropy alloys have gained significant attention in the design of nuclear structural materials. However, how they perform under successive bombardments remains unclear. In this study, molecular dynamics simulations were used to investigate the irradiation resistance of equiatomic CoCrCuFeNi HEA compared to Ni metal. The evolution of defects such as point defects, defect clusters, and dislocations after 400 bombardments was examined. The results showed that CoCrCuFeNi had fewer point defects, smaller interstitial clusters size, lower interstitial-type Frank partial dislocation density, shorter average interstitial-type Frank partial dislocation length, and higher average vacancy formation energy than Ni. These findings suggest that CoCrCuFeNi has superior radiation resistance under successive bombardments due to its high entropy effect.
ACTA METALLURGICA SINICA-ENGLISH LETTERS
(2023)
Article
Materials Science, Ceramics
Jingyi Hu, Xiang Xu, Yongcheng Cui, Mingxian Xu, Xiaojin Gao, Xiaomei Ji
Summary: Metallic glasses have unique characteristics, which have attracted extensive academic attention. However, the limited glass-forming ability hinders the design of new metallic glass systems. Machine learning models can predict alloy properties based on experimental data and aid in the design of new alloy systems. In this paper, we used an ensemble learning model with artificial neural network and random forest as base models, and proposed a data balancing method to improve model performance. Compared with other models, our approach achieved significant improvements in loss reduction and data balancing.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Chemistry, Physical
Bruno Hessel Silva, Claudia Zlotea, Yannick Champion, Walter Jose Botta, Guilherme Zepon
Summary: The study found that the three designed BCC multicomponent alloys exhibited high hydrogen absorption capacity at room temperature, forming FCC hydrides with high absorption capabilities. All three alloys showed a two-step hydrogenation sequence, indicating the formation of an intermediate BCC monohydride before the formation of the FCC dihydride. Additionally, the three alloys had similar values of enthalpy and entropy of hydrogenation, suggesting consistency in thermodynamic properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Nanoscience & Nanotechnology
Irina Belova, Mohammad Afikuzzaman, Graeme E. Murch
Summary: The analysis of interdiffusion in multicomponent alloys is approached using a new mathematical method that fits composition profiles and determines interdiffusion coefficients. Small differences in composition profiles can lead to significant variations in interdiffusion coefficients. The new approach shows excellent performance in experimental results.
SCRIPTA MATERIALIA
(2021)
Review
Materials Science, Multidisciplinary
Zhouran Zhang, David E. J. Armstrong, Patrick S. Grant
Summary: High-entropy alloys (HEAs) have potential for intriguing combinations of mechanical and other properties, with focus on irradiation response such as high phase stability and resistance to radiation-induced segregation. The Cantor alloy and its derivatives exhibit encouraging irradiation resistance superior to traditional dilute alloys, showing smaller size but higher number density of dislocation loops, significantly lower extent of swelling and improved resistance to He bubble growth. Future research directions for irradiation resistant HEAs are suggested.
PROGRESS IN MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Zhukun Zhou, Zifeng Guo, William L. Johnson, Mo Li
Summary: Crystal to glass transition under mechanical loading is common in various natural and artificial events. By conducting a series of tensile tests on a multicomponent alloy with strain rates ranging from 108 to 1012 1/s, we investigated the atomic mechanisms of this transition. Our molecular dynamics simulation revealed two different atomistic mechanisms related to the state and kinetics of crystal dislocations, resulting in either a first-order-like transition or a continuous transition depending on the strain rate.
Article
Chemistry, Physical
Yuqing Qiao, Congcong Du, Jingjing Tang, Peng Jia, Xiaoyu Zhang, Jing Wang, Shuaijun Ding, Yixuan Wen, Changzeng Fan, Liqiang Zhang, Jianyu Huang, Tongde Shen
Summary: This study utilized advanced electron microscopy to reveal micron/nano-scale hierarchical structures in vanadium-based alloys, highlighting the essential role of nanoprecipitates in hydrogen storage. The findings challenge conventional understanding of microstructures in MVAs and may guide the development of nanostructured hydrogen storage materials for practical applications.
Review
Materials Science, Multidisciplinary
J. J. Trujillo-Tadeo, Gurutze Arruebarrena, H. J. Dorantes-Rosales, Yoana Bilbao, Iban Vicario, Teresa Guraya, Inaki Hurtado
Summary: This paper presents a novel multicomponent alloy, Al58Zn28Mg6Si8, that incorporates concepts from high entropy alloys. The optimum alloy composition was determined using the CALPHAD method and binary and ternary diagrams. Microstructural and thermal analyses showed a complex phase structure and the evolution of the microstructure during heat treatment. The study provides valuable information for the future design of lightweight multicomponent alloys using experimental techniques and the CALPHAD approach.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Christopher A. Hareland, Gildas Guillemot, Charles-Andre Gandin, Peter W. Voorhees
Summary: A unified thermodynamic description is proposed for moving non-equilibrium interfaces in solid-solid and solid-liquid transformations. The theory applies to concentrated multicomponent alloys with diffusion in both phases or only in the parent phase, and considers energy dissipation due to solute drag. The study reveals that solute drag affects both the velocity of the interface and the distribution coefficients for the compositions of the two phases at the interface.
Article
Materials Science, Multidisciplinary
Rui Wang, Zhiwei Chen, Yue Shu, Yeping Lin, Zhixiao Liu, Huiqiu Deng, Wangyu Hu, Tengfei Yang
Summary: This work used molecular dynamics simulation to study the evolution of displacement cascades in AlxCoCrFeNi high entropy alloys (HEAs) with different Al contents. The results showed that the amount of peak Frenkel pairs and recombination efficiency of Frenkel pairs in the displacement cascades increased with Al content. The amount of surviving defects depended on the competition between the decrease of atomic displacement energies and prolonged thermal spike induced by Al content. Additionally, the addition of oversized alloying elements introduced two opposite effects in the primary damage stage of HEAs.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Engineering, Chemical
K. Suliz, A. Miller, K. Ivanov, A. Pervikov
Summary: This research work demonstrates the possibility of obtaining multicomponent metal nanoparticles through joint electrical explosion of wires made of different metals/alloys, using an AlCrFeCuNi alloy as an example. The analysis reveals that the nanoparticles have a lognormal size distribution, with an average size of 40 nm. The nanocrystalline structure of the nanoparticles consists of two phases based on BCC and FCC lattices. The findings suggest that the technique of joint electrical explosion shows promise for producing multicomponent metal nanoparticles.
Article
Engineering, Chemical
M. A. Avila-Rubio, C. Carreno-Gallardo, J. M. Herrera-Ramirez, B. A. Garcia-Grajeda, F. A. Perez-Gonzalez, J. H. Ramirez-Ramirez, N. F. Garza-Montes-de-Oca, F. J. Baldenebro-Lopez
Summary: High entropy alloys were designed from equiatomic multicomponent systems using powder metallurgy. Mo-containing systems exhibited the highest microhardness in both milled and sintered conditions, with alloy grain sizes in the nano scale.
ADVANCED POWDER TECHNOLOGY
(2021)
Article
Nanoscience & Nanotechnology
Zuohong Gu, Yunxuan Zhou, Quan Dong, Guangming He, Jinghao Cui, Jun Tan, Xianhua Chen, Bin Jiang, Fusheng Pan, Juergen Eckert
Summary: Magnesium alloys have great potential for applications in various industries due to their light weight and high strength. However, their low strength and stiffness limit their large-scale use. In this study, a series of lightweight multicomponent alloys with high strength and high Young's modulus were successfully designed and prepared. These alloys exhibited exceptional compressive strength and high Young's modulus, which may have implications for the design of high strength and high stiffness magnesium alloys and composites.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Takeshi Nagase, Mitsuharu Todai, Pan Wang, Shi-Hai Sun, Takayoshi Nakano
Summary: The design and development of TiZrHfAl medium entropy alloy and TiZrHfAlNb0.2 and TiZrHfAlV0.2 high entropy alloys were discussed, focusing on alloy parameters, ground state diagrams, and phase diagrams. Rapid solidification effectively suppressed intermetallic compound formation, resulting in differences in constituent phases and Vickers hardness between ingots and melt-spun ribbons.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
David A. Garfinkel, Nan Tang, Grace Pakeltis, Reece Emery, Ilia N. Ivanov, Dustin A. Gilbert, Philip D. Rack
Summary: The magnetic and optical properties of AuxCo1-x thin films and nanoparticles can be tuned by controlling their chemical composition and morphology. Annealing leads to phase separation and enhances the magnetic properties. The optical properties are greatly influenced by the chemical morphology, where phase separation enhances the quality factor and optical absorption.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Akira Takeuchi, Takeshi Wada, Takeshi Nagase, Kenji Amiya
Summary: Non-equiatomic high-entropy alloys (HEAs) with mixing entropy larger than configuration entropy were studied in Co-Cr-V-Fe-(Al, Ru, or Ni) systems. Alloys with different compositions were synthesized and their structures were analyzed using X-ray diffraction and scanning electron microscopy. Thermodynamic calculations showed that Al-30, Ru-30, and Ni-30 alloys had higher mixing entropy than configuration entropy at 1600 K. Additionally, a compositionally optimized Al-containing HEA with a single bcc structure was computationally predicted and experimentally verified. These findings contribute to the understanding of ultra-high mixing entropy alloys (UMHEAs) as a subset of HEAs.
MATERIALS TRANSACTIONS
(2022)
Article
Instruments & Instrumentation
Leo Saturday, Chris Luck, Leslie Wilson, Jason D. Fowlkes, Philip D. Rack, Nicholas J. Evans
Summary: This study presents a method to simulate the Spallation Neutron Source and characterize the thermal failure of NCD foils. A test stand with in situ diagnostics is used to track foil sublimation and thinning, and a COMSOL simulation is developed to assess potential changes to the NCD film and predict foil temperatures under different beam conditions.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2022)
Article
Chemistry, Multidisciplinary
Sumeer R. Khanna, Michael G. Stanford, Ivan V. Vlassiouk, Philip D. Rack
Summary: In this study, CuxN1-x alloy thin films were used as catalysts for graphene growth at atmospheric pressure. By adjusting the alloy composition, the growth of graphene was controlled. The results showed that graphene primarily grew as a single layer when the Cu concentration (x) was above 69 at.%.
Article
Nanoscience & Nanotechnology
John Lasseter, Philip D. Rack, Steven J. Randolph
Summary: In this study, a method for selectively depositing 3D nanostructures using photothermal transport is reported. The ability to initiate the process on sub-diffraction-limit nanoscale features is demonstrated. Thermal simulations show that the geometric shape and optical and thermal properties of the nanostructures are crucial for controlling the CVD reaction.
ACS APPLIED NANO MATERIALS
(2022)
Article
Instruments & Instrumentation
Leo Saturday, Leslie Wilson, Philip D. Rack, Nicholas J. Evans
Summary: This study compares the performance of nanocrystalline diamond stripper foils with microcrystalline alternatives under thermal load conditions. An electron beam mimic is used to evaluate their power dissipation and thermal durability, and postmortem testing is conducted to determine their physical properties.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2022)
Article
Materials Science, Multidisciplinary
Akira Takeuchi, Takeshi Wada, Kenji Amiya, Hidemi Kato, Takeshi Nagase
Summary: This study designed four Mo-Ni-Rh-Ru and Fe-Mo-Ni-Rh-Ru high-entropy alloys, and confirmed their hexagonal close-packed crystal structures through X-ray diffraction and scanning electron microscopy. The Fe20Mo20Ni20Rh20Ru20 alloy exhibited significantly higher mixing entropy than configuration entropy after annealing at 1700K for 1 hour, indicating its ultrahigh-mixing-entropy character.
MATERIALS TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Jason D. Fowlkes, Robert Winkler, Philip D. Rack, Harald Plank
Summary: This article presents an electron dose compensation strategy, called DBEA, to address the structural artifact issue caused by temperature gradient in 3D nanoprinting using focused electron beam-induced deposition. By modulating the electron dose, the deviations caused by temperature variations can be corrected, thus improving the printing accuracy.
Article
Chemistry, Multidisciplinary
John Lasseter, Philip D. D. Rack, Steven J. J. Randolph
Summary: This study demonstrates the selective growth of high-purity gold films onto nanoscale 3D architectures using the Me2Au (acac) precursor and pulsed laser pyrolytic chemical vapor deposition. The high thermal resistance of the nanoscale geometries enables selective deposition. The effects of laser irradiance, pulse width, and precursor pressure on the growth rate were explored, and feature-targeting resolutions of approximately 100 and 5 μm were achieved using diode lasers coupled to multimode (915 nm) and single mode (785 nm) fiber optics, respectively. Finite element thermal modeling was used to rationalize the experimental results.
Article
Materials Science, Multidisciplinary
Takeshi Nagase
Summary: An immiscible alloy with an amorphous phase, Al-Co-La-Bi, was designed using a combination of empirical alloy parameters, predicted ground state diagram, and thermodynamic calculations. The solidification microstructure of the alloy was investigated, revealing the presence of Bi-La intermetallic globules embedded in an amorphous matrix. STEM observation further showed the microstructure of oxygen-enriched globules with double shell layers in the alloy.
MATERIALS TRANSACTIONS
(2023)
Article
Materials Science, Multidisciplinary
Takeshi Nagase, Tomoyuki Terai, Mitsuaki Matsumuro, Mamoru Takemura
Summary: The study categorized the solidification microstructure in Fe-based Fe-X-based metallic glasses with liquid phase separation. Only Fe-Cu-based and Fe-Ag-based metallic glasses were reported to have liquid phase separation among Fe-X-based alloys. Fe-P-C-Ag immiscible metallic glasses with liquid phase separation were successfully designed using alloy parameters, ground state diagrams, and phase diagrams. Macroscopically separated ribbons composed of FCC-Ag entangled ribbons and Fe-P-C metallic glass ribbons were obtained by melt-spinning method. The formation mechanism of the macroscopically separated ribbons in Fe-P-C-Ag immiscible metallic glasses was described with the behavior of liquid phase separation and the melt-spinning process.
MATERIALS TRANSACTIONS
(2023)
Article
Materials Science, Multidisciplinary
Takeshi Nagase, Takuya Tamura
Summary: In this study, the distribution of Cu in high-entropy alloys (HEAs) with Cu as the main constituent element was investigated. Based on the classification of HEAs, those with Cu as the casting material were classified as (1) 3d transition metal-based HEAs, such as Co, Cr, Fe, Mn, Ni, and Cu (3dHEAs), and (2) high-entropy brasses based on the Cu-Zn alloy system and high-entropy bronzes based on the Cu-Sn and/or Cu-Al alloy systems. In the case of 3d-HEAs with Cu, the distribution of Cu in the ingots exhibited three tendencies: (1-1) segregation from the dendrite to the residual liquid, resulting in the formation of Cu-rich interdendritic regions in the ingots; (1-2) liquid-phase separation resulting in the formation of a Cu-rich liquid, which formed a macroscopically phase-separated structure; and (1-3) the dispersion of fine Cu precipitates embedded in the solid solution matrix.
MATERIALS TRANSACTIONS
(2023)
Article
Education, Special
Jason D. Fowlkes, Robert Winkler, Philip D. Rack, Harald Plank
Summary: 3D nanoprinting using focused electron beam-induced deposition is susceptible to structural distortions caused by temperature gradients. In this study, an electron dose compensation strategy called the Decelerating Beam Exposure Algorithm (DBEA) is proposed to correct for nanowire bending during computer-aided design. The DBEA utilizes an analytical solution derived from 3D nanoprinting simulations to offset undesired heating effects. This compensation strategy has the potential to improve the fidelity of 3D nanoscale printing.
RESEARCH IN AUTISM SPECTRUM DISORDERS
(2023)
Article
Chemistry, Multidisciplinary
Jason D. Fowlkes, Robert Winkler, Philip D. Rack, Harald Plank
Summary: 3D nanoprinting using focused electron beam-induced deposition often results in structural artifacts caused by temperature gradients during the deposition process. Researchers have developed an electron dose compensation strategy to correct for these artifacts and improve the precision of 3D nanoprinting.
