Article
Materials Science, Multidisciplinary
A. Oudriss, F. Martin, J. Creus, J. Bouhattate, L. Marchetti, X. Feaugas
Summary: The multiscale impact of dislocation patterns on hydrogen diffusion and trapping mechanisms in nickel single crystals has been investigated. A comprehensive analysis of dislocation densities, distribution, internal stresses, and vacancies concentration was performed at different levels of plastic deformation to characterize the trapping sites and their impact on diffusion coefficient. An original analyze combining electrochemical permeation and thermal desorption mass spectroscopy was used to study the factors governing hydrogen distributions. The results showed that hydrogen diffusion was slowed down by trapping with dislocations at different scales, and reversible trapping was associated with the elastic field of dislocations while irreversible trapping was associated with the core of dislocations and vacancies. Furthermore, an implication of long-range internal stress in the increase of apparent hydrogen solubility was observed in relation to dislocation cells formation, and the contribution of vacancies to hydrogen trapping was demonstrated with competition between the formation of vacancies induced by plastic strain and hydrogen ingress.
Article
Chemistry, Physical
Dannisa R. Chalfoun, Mariano A. Kappes, Pablo Bruzzoni, Mariano Iannuzzi
Summary: Hydrogen permeation experiments were conducted on quenched and tempered low alloy steels with varying Ni contents at different temperatures. The results showed that increasing Ni concentration decreases the permeation coefficient, apparent diffusion coefficient, and hydrogen concentration on the charging surface. Additionally, the study calculated the hydrogen binding energy and trap density, and found that they are not clearly correlated with Ni content.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Multidisciplinary
Yuhei Ogawa, Kohei Noguchi, Osamu Takakuwa
Summary: This study investigated the tensile mechanical properties of a Ni-based superalloy 718 precharged with approximately 90 mass ppm hydrogen under a wide range of temperatures, aiming to clarify the uncertainties surrounding the hydrogen-related embrittlement mechanisms of the material. The study found that hydrogen had a substantial detrimental effect on the ductility of the material in the near-ambient to high-temperature range, resulting from microcrack initiations along annealing twin boundaries and crystallographic slip planes. Additionally, the study revealed that the dynamic hydrogen-dislocation interaction was not important for embrittlement. By combining the insights gained from the test program, a new model for the nucleation process of hydrogen-induced fracturing was established.
Article
Nanoscience & Nanotechnology
K. Wada, C. Shibata, H. Enoki, T. Iijima, J. Yamabe
Summary: Industrial-grade pure nickel, NI-201, was subjected to tensile testing in high-pressure hydrogen gas under various conditions. The degree of hydrogen embrittlement (HE) was affected by the testing temperature and strain rate, with higher strain rates and lower temperatures resulting in less HE. While hydrogen trapped at grain boundaries dominated HE in hydrogen-charged cases, hydrogen supply to grain boundaries was required in gaseous hydrogen cases. The contribution of hydrogen-dislocation interaction was found to be minor, and a HE model considering hydrogen diffusion along grain boundaries from the crack tip successfully explained the experimental results.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Chemistry, Physical
Kun Yi, Rui Ma, Siqi Xiang, Xuebing Liu, Changhao Liu, Xinfang Zhang, Yabo Fu
Summary: This study introduces an electric pulse method to solve the issue of hydrogen embrittlement in ultrahigh-strength automotive steel. By removing hydrogen, the resistance to hydrogen embrittlement is improved, leading to better performance compared to traditional heat treatment methods.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Multidisciplinary
Y. Aboura, D. F. Martelo, R. Morana, R. Akid, K. L. Moore
Summary: This study investigated the hydrogen induced cracking behavior of O&G nickel alloy 625+ (UNS N07716) using deuterium as an isotopic tracer. The results showed enrichments at dislocation slip bands, twin boundary, and grain boundary features, providing experimental evidence of the phenomenon. Analysis using scanning electron microscopy and energy dispersive X-ray techniques helped in identifying the microstructural features corresponding to deuterium enrichments.
Article
Mechanics
Viktor Kharin
Summary: This paper describes the delivery of hydrogen to different microstructural positions based on comprehensive diffusion trapping theory and reveals the potential of these microstructural features to carry out the mechanistic effects of hydrogen and retard hydrogen accumulation in fracture nuclei.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Qian Yan, Luchun Yan, Xiaolu Pang, Kewei Gao
Summary: This study investigated the influence of Cu precipitations on hydrogen trapping capability and hydrogen embrittlement (HE) in aged martensitic stainless steel. The results showed a significant decrease in the hydrogen diffusion coefficient and a substantial increase in the hydrogen content in specimens containing Cu precipitations. The specimens with peak-aged (1 h) Cu precipitations exhibited the highest HE susceptibility, as a result of abundant hydrogen trapped by coherent Cu precipitations with the matrix and escaped during the tensile process.
Article
Materials Science, Multidisciplinary
Kazuki Okuno, Kenichi Takai
Summary: Factors promoting hydrogen-related intergranular fracture in tempered martensitic steel's elastic region were identified through frozen-in hydrogen distribution and tensile tests at -196°C. Results showed hydrogen embrittlement associated with intergranular fracture after precharging with hydrogen, while hydrogen embrittlement was also observed after preloading with elastic stress just before fracture strength at room temperature. The study revealed that reversibly accumulated hydrogen due to stress-induced diffusion onto prior austenite grain boundaries during stress loading at room temperature was responsible for intergranular fracture.
Article
Chemistry, Physical
Lixia Zhu, Jinheng Luo, Shunli Zheng, Shuaijun Yang, Jun Hu, Zhong Chen
Summary: In this study, the hydrogen diffusion mechanisms in doped α-Fe were investigated using first-principles calculations. It was found that the hydrogen trap is a thermodynamically spontaneous process, and doping decreases the hydrogen adsorption energy due to changes in adsorption sites. Moreover, hydrogen diffusion from the surface to subsurface is crucial for the diffusion rate. Mo, Mn, and C are beneficial for increasing the energy barrier of hydrogen diffusion in the bulk and from the surface to subsurface. This research provides a promising approach to enhancing the hydrogen diffusion barrier in α-Fe.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Review
Chemistry, Physical
Paul C. Okonkwo, El Manaa Barhoumi, Ikram Ben Belgacem, Ibrahim B. Mansir, Mansur Aliyu, Wilfred Emori, Paul C. Uzoma, Wesam H. Beitelmal, Ersin Akyuz, Ahmed Bahgat Radwan, R. A. Shakoor
Summary: Hydrogen embrittlement is a well-known phenomenon in high-strength and storage materials, causing subcritical crack growth, fracture initiation, loss in mechanical properties, and catastrophic failure. The fundamental mechanism of hydrogen embrittlement remains unclear, although various mechanisms responsible for crack development, growth, and fracture have been discussed and reported.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Materials Science, Multidisciplinary
Alireza Tondro, Hamidreza Abdolvand
Summary: This study investigates the effects of localized stresses on the redistribution of hydrogen atoms during the formation of zirconium hydrides, showing that hydrogen atoms tend to diffuse towards the tips of hydrides and away from their sides, leading to hydride propagation along their axial direction. It is also found that under tensile stress, hydrides tend to form and propagate within hard grains.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Engineering, Mechanical
Erfan Abedi Esfahani, Farhad Shahriari Nogorani, Mohammad Nasr Esfahani
Summary: This study investigates the effects of thermo-mechanical factors on hydrogen generation in lubricated rubbing contacts using in-situ hydrogen uptake technique and molecular dynamics simulations. Experimental measurements of hydrogen uptake on AISI 52100 bearing steel are conducted at temperatures of 27 degrees C and 85 degrees C with applied pressures of 140 kPa and 350 kPa. Atomic simulations are used to model the experimental data through the reactive force field potential. The hydrogen generation associated with Poly Alpha Olefin decomposition is analyzed using pair distribution function calculations. The findings show enhanced hydrocarbon decomposition with increasing temperature and pressure, as well as a critical pressure requirement for decomposition at ambient temperature. The critical pressure for lubricant degradation decreases with increasing temperature. This study emphasizes the importance of considering thermo-mechanical effects in the design and development of lubricated rubbing contacts.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Lanxi Feng, Xiaoqing Zhang, Wanghui Li, Meizhen Xiang, Xiaohu Yao
Summary: Hydrogen embrittlement in metals has long been a concern, but the fundamental mechanisms in dynamic events are not well understood. Atomic simulations reveal the anisotropic effects of hydrogen atoms on spall strength in different crystal orientations. Hydrogen atoms prevent phase transition and enhance spall strength in [100] crystal orientation, while in [111] crystal orientation, hydrogen atoms promote dislocation formations and lower spall strength. In nanocrystalline samples, hydrogen atoms slightly increase spall strength by disturbing grain boundaries. This work provides insights into hydrogen effects on metals under dynamic loading, benefiting materials and mechanics research communities.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
S. S. Shishvan, G. Csanyi, V. S. Deshpande
Summary: The susceptibility of ferritic steels to hydrogen embrittlement increases with decreasing strain rates. This is explained by the diffusion of hydrogen. However, for pre-charged specimens, lattice diffusion dominates and has no effect at such low strain rates. A model based on the Hydrogen Induced Fast-Fracture (HIFF) mechanism is presented to rationalize the strain rate dependence of hydrogen embrittlement. The dominant kinetics governing the strain rate sensitivity is the hydrogen desorption rates from cavity surfaces.
Correction
Materials Science, Multidisciplinary
A. D. Boccardo, M. Tong, S. B. Leen, D. Tourret, J. Segurado
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Tao Li, Qing Hou, Jie-chao Cui, Jia-hui Yang, Ben Xu, Min Li, Jun Wang, Bao-qin Fu
Summary: This study investigates the thermal and defect properties of AlN using molecular dynamics simulation, and proposes a new method for selecting interatomic potentials, developing a new model. The developed model demonstrates high computational accuracy, providing an important tool for modeling thermal transport and defect evolution in AlN-based devices.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Shin-Pon Ju, Chao-Chuan Huang, Hsing-Yin Chen
Summary: Amorphous boron nitride (a-BN) is a promising ultralow-dielectric-constant material for interconnect isolation in integrated circuits. This study establishes a deep learning potential (DLP) for different forms of boron nitride and uses molecular dynamics simulations to investigate the mechanical behaviors of a-BN. The results reveal the structure-property relationships of a-BN, providing useful insights for integrating it in device applications.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
M. Salman, S. Schmauder
Summary: Shape memory polymer foams (SMPFs) are lightweight cellular materials that can recover their undeformed shape through external stimulation. Reinforcing the material with nano-clay filler improves its physical properties. Multiscale modeling techniques can be used to study the thermomechanical response of SMPFs and show good agreement with experimental results.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Laura Gueci, Francesco Ferrante, Marco Bertini, Chiara Nania, Dario Duca
Summary: This study investigates the acidity of 30 Bronsted sites in the beta-zeolite framework and compares three computational methods. The results show a wide range of deprotonation energy values, and the proposed best method provides accurate calculations.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
K. A. Lopes Lima, L. A. Ribeiro Junior
Summary: Advancements in nanomaterial synthesis and characterization have led to the discovery of new carbon allotropes, including biphenylene network (BPN). The study finds that BPN lattices with a single-atom vacancy exhibit higher CO2 adsorption energies than pristine BPN. Unlike other 2D carbon allotropes, BPN does not exhibit precise CO2 sensing and selectivity by altering its band structure configuration.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Jay Kumar Sharma, Arpita Dhamija, Anand Pal, Jagdish Kumar
Summary: In this study, the quaternary Heusler alloys LiAEFeSb were investigated for their crystal structure, electronic properties, and magnetic behavior. Density functional theory calculations revealed that LiSrFeSb and LiBaFeSb exhibit half-metallic band structure and 100% spin polarization, making them excellent choices for spintronic applications.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Roman A. Eremin, Innokentiy S. Humonen, Alexey A. Kazakov, Vladimir D. Lazarev, Anatoly P. Pushkarev, Semen A. Budennyy
Summary: Computational modeling of disordered crystal structures is essential for studying composition-structure-property relations. In this work, the effects of Cd and Zn substitutions on the structural stability of CsPbI3 were investigated using DFT calculations and GNN models. The study achieved accurate energy predictions for structures with high substitution contents, and the impact of data subsampling on prediction quality was comprehensively studied. Transfer learning routines were also tested, providing new perspectives for data-driven research of disordered materials.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Zhixin Sun, Hang Dong, Yaohui Yin, Ai Wang, Zhen Fan, Guangyong Jin, Chao Xin
Summary: In this study, the crystal structure, electronic structure, and optical properties of KH2PO4: KDP crystals under different pressures were investigated using the generalized gradient approximate. It was found that high pressure caused a phase transition in KDP and greatly increased the band gap. The results suggest that high pressure enhances the compactness of KDP and improves the laser damage threshold.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Tingting Yu
Summary: This study presents atomistic simulations revealing that an increase in driving force may result in slower grain boundary movement and switches in the mode of grain boundary shear coupling migration. Shear coupling behavior is found to effectively alleviate stress and holds potential for stress relaxation and microstructure manipulation in materials.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Y. Zhang, X. Q. Deng, Q. Jing, Z. S. Zhang
Summary: The electronic properties of C2N/antimonene van der Waals heterostructure are investigated using density functional theory. The results show that by applying horizontal strain, vertical strain, electric field, and interlayer twist, the electronic structure can be adjusted. Additionally, the band alignment and energy states of the heterostructure can be significantly changed by applying vertical strain on the twisted structure. These findings are important for controlling the electronic properties of heterostructures.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Chad E. Junkermeier, Evan Larmand, Jean-Charles Morais, Jedediah Kobebel, Kat Lavarez, R. Martin Adra, Jirui Yang, Valeria Aparicio Diaz, Ricardo Paupitz, George Psofogiannakis
Summary: This study investigates the adsorption properties of carbon dioxide (CO2), methane (CH4), and dihydrogen (H2) in carbophenes functionalized with different groups. The results show that carbophenes can be promising adsorbents for these gases, with high adsorption energies and low desorption temperatures. The design and combination of functional groups can further enhance their adsorption performance.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Y. Borges, L. Huber, H. Zapolsky, R. Patte, G. Demange
Summary: Grain boundary structure is closely related to solute atom segregation, and machine learning can predict the segregation energy density. The study provides a fresh perspective on the relationship between grain boundary structure and segregation properties.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
M. R. Jones, L. T. W. Fey, I. J. Beyerlein
Summary: In this work, a three-dimensional ab-initio informed phase-field-dislocation dynamics model combined with Langevin dynamics is used to investigate glide mechanisms of edge and screw dislocations in Nb at finite temperatures. It is found that the screw dislocation changes its mode of glide at two distinct temperatures, which coincides with the thermal insensitivity and athermal behavior of Nb yield strengths.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Joshua A. Vita, Dallas R. Trinkle
Summary: This study introduces a new machine learning model framework that combines the simplicity of spline-based potentials with the flexibility of neural network architectures. The simplified version of the neural network potential can efficiently describe complex datasets and explore the boundary between classical and machine learning models. Using spline filters for encoding atomic environments results in interpretable embedding layers that can incorporate expected physical behaviors and improve interpretability through neural network modifications.
COMPUTATIONAL MATERIALS SCIENCE
(2024)