Pub Date : 2024-06-06DOI: 10.1088/1361-651X/ad54e2
Li Meng, A. Tabiei
Phase field model has been investigated for brittle fracture in many static and dynamic scenarios, but its applications to ductile fracture is not as common as brittle fracture, especially implementing in software LS-DYNA with explicit scheme. In this study, an efficient LS-DYNA implementation of the phase field modeling of ductile fracture is presented and both with and without the split of elastic strain energy have been considered for the damage evolution. In more detail, plasticity formulation of ductile material with isotropic hardening is briefly presented first and then the governing equations of the classical phase field model are derived, which gives the displacement-phase coupled problem. For with the split of elastic strain energy, the shear component of elastic strain energy is considered for the damage evolution. The influence of degradation function on stress–strain curve is also investigated by using three kinds of function (polynomial function, algebraic fraction function and sigmoid function), which leads to linear and nonlinear finite element method (FEM) formulation of the phase field model and Newton–Raphson method is used to solve the nonlinear FEM formulation of the phase field model. A tensile bar test shows the influence of critical energy release rate and degradation function on stress–strain curve. Mode Ⅰ failure of three-point bending test, Mode Ⅱ failure of single-edge notched plate and mixed-mode failure of asymmetrical double-notched plate verify the proposed model in this study. From these simulations, with the split of elastic strain energy shows improvements on plastic deformation than without the split of elastic strain energy.
{"title":"Phase field modeling of ductile fracture with isotropic hardening and radius return method","authors":"Li Meng, A. Tabiei","doi":"10.1088/1361-651X/ad54e2","DOIUrl":"https://doi.org/10.1088/1361-651X/ad54e2","url":null,"abstract":"Phase field model has been investigated for brittle fracture in many static and dynamic scenarios, but its applications to ductile fracture is not as common as brittle fracture, especially implementing in software LS-DYNA with explicit scheme. In this study, an efficient LS-DYNA implementation of the phase field modeling of ductile fracture is presented and both with and without the split of elastic strain energy have been considered for the damage evolution. In more detail, plasticity formulation of ductile material with isotropic hardening is briefly presented first and then the governing equations of the classical phase field model are derived, which gives the displacement-phase coupled problem. For with the split of elastic strain energy, the shear component of elastic strain energy is considered for the damage evolution. The influence of degradation function on stress–strain curve is also investigated by using three kinds of function (polynomial function, algebraic fraction function and sigmoid function), which leads to linear and nonlinear finite element method (FEM) formulation of the phase field model and Newton–Raphson method is used to solve the nonlinear FEM formulation of the phase field model. A tensile bar test shows the influence of critical energy release rate and degradation function on stress–strain curve. Mode Ⅰ failure of three-point bending test, Mode Ⅱ failure of single-edge notched plate and mixed-mode failure of asymmetrical double-notched plate verify the proposed model in this study. From these simulations, with the split of elastic strain energy shows improvements on plastic deformation than without the split of elastic strain energy.","PeriodicalId":18648,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141381367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Three methods are used to predict the martensitic transformation start temperature (Ms) of steel. Based on the database containing 832 compositions and corresponding Ms data, prediction models are built, modified, and trained. Firstly, Ms was re-calculated by establishing a thermodynamic model to link the martensitic transformation driving force (Gibbs free energy difference of martensite and austenite) with resistance (elastic strain energy, plastic strain energy, interface energy, and shearing energy). Secondly, the existing Ms data is cleaned and re-predicted using traditional empirical formulas within different composition application ranges. Thirdly, four different algorithms in machine learning including random forest (RF), k nearest neighbor (KNN), linear regression (LR), and decision tree (DT) are trained to predict 832 new Ms values. By comparing the Ms results re-predicted by the mentioned three methods with the original Ms values, the accuracy is evaluated to identify the optimal prediction model.
采用三种方法预测钢的马氏体转变起始温度（Ms）。基于包含 832 种成分和相应 Ms 数据的数据库，建立、修改和训练了预测模型。首先，通过建立热力学模型，将马氏体转变驱动力（马氏体和奥氏体的吉布斯自由能差）与阻力（弹性应变能、塑性应变能、界面能和剪切能）联系起来，重新计算 Ms。其次，对现有的 Ms 数据进行清理，并在不同成分应用范围内使用传统经验公式重新预测。第三，训练四种不同的机器学习算法，包括随机森林 (RF)、k 近邻 (KNN)、线性回归 (LR) 和决策树 (DT)，以预测 832 个新的 Ms 值。通过将上述三种方法重新预测的 Ms 结果与原始 Ms 值进行比较，评估准确度，从而确定最佳预测模型。
{"title":"Prediction of Martensitic Transformation Start Temperature of Steel Using Thermodynamic Model, Empirical Formulas, and Machine Learning Models","authors":"Zidong Lin, Jiaqi Wang, Chenxv Zhou, Zhen Sun, Yanlong Wang, Xinghua Yu","doi":"10.1088/1361-651x/ad54e0","DOIUrl":"https://doi.org/10.1088/1361-651x/ad54e0","url":null,"abstract":"\u0000 Three methods are used to predict the martensitic transformation start temperature (Ms) of steel. Based on the database containing 832 compositions and corresponding Ms data, prediction models are built, modified, and trained. Firstly, Ms was re-calculated by establishing a thermodynamic model to link the martensitic transformation driving force (Gibbs free energy difference of martensite and austenite) with resistance (elastic strain energy, plastic strain energy, interface energy, and shearing energy). Secondly, the existing Ms data is cleaned and re-predicted using traditional empirical formulas within different composition application ranges. Thirdly, four different algorithms in machine learning including random forest (RF), k nearest neighbor (KNN), linear regression (LR), and decision tree (DT) are trained to predict 832 new Ms values. By comparing the Ms results re-predicted by the mentioned three methods with the original Ms values, the accuracy is evaluated to identify the optimal prediction model.","PeriodicalId":18648,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141381445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As one of the most promising lightweight high-temperature structural materials in the future, the surface quality of γ-TiAl alloys has a great influence on the performance of the workpieces, and the tool parameters are an important factor affecting the machining results. In this study, molecular dynamics simulations of the nano-cutting process of polycrystalline γ-TiAl alloys with different tool parameters were carried out. The results show that increasing the tool rake angle and decreasing the tool edge radius within a certain range helps to reduce the average cutting force, cutting force fluctuation, cutting temperature, and stabilize the cutting process, while the change of the tool clearance angle has less influence on the cutting process. In contrast, negative rake angle cutting is more likely to produce grain rotation and grain boundary steps in the processed substrate and increase the processed surface roughness than positive rake angle cutting; increasing the tool rake angle within a certain range will weaken the elastic recovery effect of the substrate. During cutting at a positive rake angle, whether a portion of the substrate is prone to slip toward the surface of the substrate, thereby reducing the surface quality, depends on the relative state of grain orientation and force applied in the substrate.
{"title":"Molecular dynamics simulation of the effect of tool parameters on nano-cutting of polycrystalline γ-TiAl alloys","authors":"Yichao Zhou, Hui Cao, Baocheng Zhou, Haiyan Li, Wenke Chen, Chunli Lei, Ruicheng Feng","doi":"10.1088/1361-651X/ad54e3","DOIUrl":"https://doi.org/10.1088/1361-651X/ad54e3","url":null,"abstract":"As one of the most promising lightweight high-temperature structural materials in the future, the surface quality of γ-TiAl alloys has a great influence on the performance of the workpieces, and the tool parameters are an important factor affecting the machining results. In this study, molecular dynamics simulations of the nano-cutting process of polycrystalline γ-TiAl alloys with different tool parameters were carried out. The results show that increasing the tool rake angle and decreasing the tool edge radius within a certain range helps to reduce the average cutting force, cutting force fluctuation, cutting temperature, and stabilize the cutting process, while the change of the tool clearance angle has less influence on the cutting process. In contrast, negative rake angle cutting is more likely to produce grain rotation and grain boundary steps in the processed substrate and increase the processed surface roughness than positive rake angle cutting; increasing the tool rake angle within a certain range will weaken the elastic recovery effect of the substrate. During cutting at a positive rake angle, whether a portion of the substrate is prone to slip toward the surface of the substrate, thereby reducing the surface quality, depends on the relative state of grain orientation and force applied in the substrate.","PeriodicalId":18648,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141378379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-06DOI: 10.1088/1361-651x/ad4c82
Izumi Takahara, Kiyou Shibata, Teruyasu Mizoguchi
Crystal orbital overlap population (COOP) is one of the effective tools for chemical-bonding analysis, and thus it has been utilized in the materials development and characterization. In this study, we developed a code to perform the COOP-based chemical-bonding analysis based on the wave function obtained from a first principles all-electron calculation with numeric atom-centered orbitals. The chemical-bonding analysis using the developed code was demonstrated for F2, Si, CaC6, and metals including Ti and Nb. Furthermore, we applied the method to analyze the chemical-bonding changes associated with a Li intercalation in three representative layered materials: graphite, MoS2, and ZrNCl, because of their great industrial importance, particularly for the applications in battery and superconducting materials. The COOP analysis provided some insights for understanding the intercalation mechanism and the stability of the intercalated materials from a chemical-bonding viewpoint.
晶体轨道重叠群（COOP）是化学键分析的有效工具之一，因此在材料开发和表征中得到了广泛应用。在本研究中，我们开发了一种代码，以第一原理全电子计算获得的波函数为基础，利用数值原子中心轨道进行基于 COOP 的化学键分析。使用开发的代码对 F2、Si、CaC6 以及包括 Ti 和 Nb 在内的金属进行了化学键分析。此外，由于石墨、MoS2 和 ZrNCl 这三种具有代表性的层状材料在工业上的重要性，特别是在电池和超导材料中的应用，我们应用该方法分析了与锂插层相关的化学键变化。COOP 分析为从化学键角度理解插层材料的插层机理和稳定性提供了一些启示。
{"title":"Crystal orbital overlap population based on all-electron ab initio simulation with numeric atom-centered orbitals and its application to chemical-bonding analysis in Li-intercalated layered materials","authors":"Izumi Takahara, Kiyou Shibata, Teruyasu Mizoguchi","doi":"10.1088/1361-651x/ad4c82","DOIUrl":"https://doi.org/10.1088/1361-651x/ad4c82","url":null,"abstract":"Crystal orbital overlap population (COOP) is one of the effective tools for chemical-bonding analysis, and thus it has been utilized in the materials development and characterization. In this study, we developed a code to perform the COOP-based chemical-bonding analysis based on the wave function obtained from a first principles all-electron calculation with numeric atom-centered orbitals. The chemical-bonding analysis using the developed code was demonstrated for F<sub>2</sub>, Si, CaC<sub>6</sub>, and metals including Ti and Nb. Furthermore, we applied the method to analyze the chemical-bonding changes associated with a Li intercalation in three representative layered materials: graphite, MoS<sub>2</sub>, and ZrNCl, because of their great industrial importance, particularly for the applications in battery and superconducting materials. The COOP analysis provided some insights for understanding the intercalation mechanism and the stability of the intercalated materials from a chemical-bonding viewpoint.","PeriodicalId":18648,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141546735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-06DOI: 10.1088/1361-651x/ad54e1
G. B. Acharya, Se-Hun Kim, Madhav Prasad Ghimire
The application of semiconductors with optical properties has grown significantly in the development of semiconductor photovoltaics. Here, we explore the electronic and optical properties of ternary transition metal sulfide Rb2Ni3S4 by means of density functional theory. From the structural perspective, Ni atoms is found to form a kagome-like lattice in a two-dimensional plane of Rb2Ni3S4. From our calculations, Rb2Ni3S4 is found to be a semiconductor with an indirect band gap of ∼0.67 eV. Strong hybridization was observed between the S-3p with the Ni-3dxz and Ni-3dyz orbitals. Interestingly, a flat band was noticed below the Fermi level demonstrating one significant feature of kagome lattice. From the optical calculations, Rb2Ni3S4 is found to exhibit optical activity in both the visible and lower ultraviolet regions of the incident photon energies. The optical response suggests this material may be a potential candidate for opto-electronic device, given its ability to interact with light across a broad range of wavelengths. This work is expected to motivate the experimental group for transport measurements and may provide a new foundation in optics.
{"title":"Electronic and optical properties of ternary kagome Rb2Ni3S4: A density functional study","authors":"G. B. Acharya, Se-Hun Kim, Madhav Prasad Ghimire","doi":"10.1088/1361-651x/ad54e1","DOIUrl":"https://doi.org/10.1088/1361-651x/ad54e1","url":null,"abstract":"\u0000 The application of semiconductors with optical properties has grown significantly in the development of semiconductor photovoltaics. Here, we explore the electronic and optical properties of ternary transition metal sulfide Rb2Ni3S4 by means of density functional theory. From the structural perspective, Ni atoms is found to form a kagome-like lattice in a two-dimensional plane of Rb2Ni3S4. From our calculations, Rb2Ni3S4 is found to be a semiconductor with an indirect band gap of ∼0.67 eV. Strong hybridization was observed between the S-3p with the Ni-3dxz and Ni-3dyz orbitals. Interestingly, a flat band was noticed below the Fermi level demonstrating one significant feature of kagome lattice. From the optical calculations, Rb2Ni3S4 is found to exhibit optical activity in both the visible and lower ultraviolet regions of the incident photon energies. The optical response suggests this material may be a potential candidate for opto-electronic device, given its ability to interact with light across a broad range of wavelengths. This work is expected to motivate the experimental group for transport measurements and may provide a new foundation in optics.","PeriodicalId":18648,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141377059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-04DOI: 10.1088/1361-651x/ad53eb
Masoud Rahbarniazi, William Curtin
The activation of prismatic slip in Mg and its alloys can be beneficial for deformation and forming. Experiments show that addition of Zn and Al solutes have a softening effect at/below room temperature, attributed to solutes facilitating basal-prism-basal cross-slip of prismatic screw dislocations, but a strengthening effect with increasing temperature. Here, the dynamic strain aging mechanism of cross-core diffusion within the prismatic edge dislocation is investigated as a possible mechanism for the strengthening at higher temperatures. First-principles calculations provide the required information on solute/dislocation interaction energies and vacancy-mediated solute migration barriers for Zn solutes around the dislocation core. Results for Mg-0.0045Zn show that cross-core diffusion notably increases the stress for prismatic edge dislocation glide but that the strengthening remains roughly 30% of the experimental strength. Other possible strengthening mechanisms of (i) solute drag of the prism edge dislocation and (ii) solute interactions and/or diffusion within the prismatic screw core, are then briefly discussed with some quantitative assessments pointing toward areas for future study.
激活镁及其合金中的棱柱滑移有利于变形和成型。实验表明，添加锌和铝溶质在室温/室温以下会产生软化效应，这是由于溶质促进了棱边螺旋位错的基底-棱边-基底交叉滑移，但随着温度的升高会产生强化效应。在此，我们研究了棱柱边位错内交叉核扩散的动态应变老化机制，以此作为高温下强化的一种可能机制。第一原理计算为差排核心周围的锌溶质提供了溶质/差排相互作用能和空位介导的溶质迁移障碍等所需信息。Mg-0.0045Zn 的结果表明，跨核扩散显著增加了棱边位错滑行的应力，但其强化作用仍约为实验强度的 30%。然后简要讨论了其他可能的强化机制：(i) 棱边位错的溶质拖曳和 (ii) 棱边螺核内的溶质相互作用和/或扩散，并进行了一些定量评估，指出了未来研究的领域。
{"title":"Strengthening of edge prism dislocations in Mg-Zn by cross-core diffusion","authors":"Masoud Rahbarniazi, William Curtin","doi":"10.1088/1361-651x/ad53eb","DOIUrl":"https://doi.org/10.1088/1361-651x/ad53eb","url":null,"abstract":"\u0000 The activation of prismatic slip in Mg and its alloys can be beneficial for deformation and forming. Experiments show that addition of Zn and Al solutes have a softening effect at/below room temperature, attributed to solutes facilitating basal-prism-basal cross-slip of prismatic screw dislocations, but a strengthening effect with increasing temperature. Here, the dynamic strain aging mechanism of cross-core diffusion within the prismatic edge dislocation is investigated as a possible mechanism for the strengthening at higher temperatures. First-principles calculations provide the required information on solute/dislocation interaction energies and vacancy-mediated solute migration barriers for Zn solutes around the dislocation core. Results for Mg-0.0045Zn show that cross-core diffusion notably increases the stress for prismatic edge dislocation glide but that the strengthening remains roughly 30% of the experimental strength. Other possible strengthening mechanisms of (i) solute drag of the prism edge dislocation and (ii) solute interactions and/or diffusion within the prismatic screw core, are then briefly discussed with some quantitative assessments pointing toward areas for future study.","PeriodicalId":18648,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141266321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-04DOI: 10.1088/1361-651x/ad53ec
Yuanyuan Tian, Qihong Fang, Junni Chen, Gangjie Luo, Chunyang Du
FeCoCrNiCu High-entropy alloys (HEAs) exhibit extraordinary mechanical properties and have the capability to withstand extreme temperatures and pressures. Their exceptional attributes make them suitable for diverse applications, from aerospace to chemical industry. We employ atomic-scale simulations to explore the effects of twinning boundary and twinning thickness on the mechanical behavior of nanotwinned FeCoCrNiCu during nanoindentation. The findings suggest that as the twinning thickness decreases within the range of 19.3 Å to 28.9 Å, both twinning partial slips and horizontal twinning partial slips gradually become dominant in governing the plastic behaviors of the nanotwinned FeCoCrNiCu, thereby resulting in an inverse Hall-Petch effect. Remarkably, when the twinning thickness is compressed below 19.3 Å, a shift in the plastic deformation mechanism emerges, triggering the conventional Hall-Petch relation. The observed Hall-Petch behavior in nanotwinned FeCoCrNiCu is attributed to the strengthening effect imparted by the twinning boundaries. Consequently, the twinning boundary play an instrumental role in steering the plastic deformation mechanism of the nanotwinned FeCoCrNiCu when the twinning thickness descends beneath 19.3 Å. This study contributes significant insights towards the design of next-generation high-performance HEAs, underpinning their potential industrial utilization.
铁铬镍铜高熵合金 (HEA) 具有非凡的机械性能，能够承受极端的温度和压力。它们的特殊属性使其适用于从航空航天到化学工业的各种应用。我们采用原子尺度模拟来探索孪晶边界和孪晶厚度对纳米孪晶铁钴铬镍铜在纳米压痕过程中机械行为的影响。研究结果表明，当孪晶厚度在 19.3 Å 至 28.9 Å 范围内减小时，孪晶部分滑移和水平孪晶部分滑移逐渐成为纳米孪晶铁钴铬镍铜塑性行为的主导，从而产生了反霍尔-佩奇效应。值得注意的是，当孪晶厚度压缩到 19.3 Å 以下时，塑性变形机制发生了转变，从而引发了传统的霍尔-佩奇关系。在纳米孪晶铁钴铬镍铜中观察到的 Hall-Petch 行为归因于孪晶边界带来的强化效应。因此，当孪晶厚度降到 19.3 Å 以下时，孪晶边界在引导纳米孪晶铁钴铬镍铜的塑性变形机制中发挥了重要作用。这项研究为下一代高性能 HEA 的设计提供了重要启示，为其潜在的工业应用奠定了基础。
{"title":"Atomic Insight into Nanoindentation Response of Nanotwinned FeCoCrNiCu High Entropy Alloys","authors":"Yuanyuan Tian, Qihong Fang, Junni Chen, Gangjie Luo, Chunyang Du","doi":"10.1088/1361-651x/ad53ec","DOIUrl":"https://doi.org/10.1088/1361-651x/ad53ec","url":null,"abstract":"\u0000 FeCoCrNiCu High-entropy alloys (HEAs) exhibit extraordinary mechanical properties and have the capability to withstand extreme temperatures and pressures. Their exceptional attributes make them suitable for diverse applications, from aerospace to chemical industry. We employ atomic-scale simulations to explore the effects of twinning boundary and twinning thickness on the mechanical behavior of nanotwinned FeCoCrNiCu during nanoindentation. The findings suggest that as the twinning thickness decreases within the range of 19.3 Å to 28.9 Å, both twinning partial slips and horizontal twinning partial slips gradually become dominant in governing the plastic behaviors of the nanotwinned FeCoCrNiCu, thereby resulting in an inverse Hall-Petch effect. Remarkably, when the twinning thickness is compressed below 19.3 Å, a shift in the plastic deformation mechanism emerges, triggering the conventional Hall-Petch relation. The observed Hall-Petch behavior in nanotwinned FeCoCrNiCu is attributed to the strengthening effect imparted by the twinning boundaries. Consequently, the twinning boundary play an instrumental role in steering the plastic deformation mechanism of the nanotwinned FeCoCrNiCu when the twinning thickness descends beneath 19.3 Å. This study contributes significant insights towards the design of next-generation high-performance HEAs, underpinning their potential industrial utilization.","PeriodicalId":18648,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141268498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-04DOI: 10.1088/1361-651x/ad53ee
Viejay Z. Ordillo, Koji Shimizu, D. Putungan, A. Santos-Putungan, Satoshi Watanabe, Rizalinda de Leon, Joey D. Ocon, K. Pilario, A. A. Padama
This paper presents a feature-centric strategy for predicting adsorption energies of key CO2 reduction reaction (CO2RR) adsorbates, CO and H species, utilizing DFT-based calculations for eight (8) adsorption sites and considering alloying effects of nine (9) transition metals at single-atom concentrations. Here, we explore a class of materials consisting of a majority host metal where individual atoms of a different element are dispersed called single-atom alloys (SAA). A total of eight (8) feature selection methods are assessed within Gradient Boosting Regression and Linear Regression models. This study proposes a practical and effective two-stage approach that narrows down the initial 86 features to subsets of 10 and 7 for CO and H adsorption energy predictions, respectively, with the arithmetic mean of valence electrons (VE-am) feature consistently emerging as highly influential, validated through permutation and Shapley additive explanations (SHAP)-based feature importance analyses. The models exhibit robust performance on unseen data, indicating their generalization capability. The findings emphasize VE-am as a potential key machine learning feature for CO2RR on SAA surfaces and underline the effectiveness of the feature-centric approach in understanding feature impacts in machine learning models for CO2RR on SAA systems. Additionally, while other features based on structural, electronic and elemental properties may not individually impact the model significantly, their collective contribution plays a vital role in achieving more accurate adsorption energy predictions.
本文提出了一种以特征为中心的策略，利用基于 DFT 计算的八（8）个吸附位点，并考虑九（9）种过渡金属在单原子浓度下的合金效应，预测二氧化碳还原反应（CO2RR）关键吸附剂（CO 和 H 物种）的吸附能。在此，我们探讨了一类由多数主金属组成的材料，其中分散着不同元素的单个原子，这种材料被称为单原子合金（SAA）。在梯度提升回归（Gradient Boosting Regression）和线性回归（Linear Regression）模型中，共评估了八（8）种特征选择方法。本研究提出了一种实用有效的两阶段方法，可将最初的 86 个特征缩小到 10 个子集和 7 个子集，分别用于 CO 和 H 吸附能预测，其中价电子算术平均值（VE-am）特征始终具有很高的影响力，这一点通过基于置换和夏普利加法解释（SHAP）的特征重要性分析得到了验证。这些模型在未见过的数据上表现出稳健的性能，表明了它们的泛化能力。研究结果强调，VE-am 是机器学习对 SAA 表面 CO2RR 的潜在关键特征，并强调了以特征为中心的方法在理解机器学习模型对 SAA 系统 CO2RR 的特征影响方面的有效性。此外，虽然基于结构、电子和元素特性的其他特征可能不会单独对模型产生重大影响，但它们的集体贡献在实现更准确的吸附能预测方面发挥着至关重要的作用。
{"title":"Two-Stage Feature Selection for Machine Learning-aided DFT-based Surface Reactivity Study on Single-Atom Alloys","authors":"Viejay Z. Ordillo, Koji Shimizu, D. Putungan, A. Santos-Putungan, Satoshi Watanabe, Rizalinda de Leon, Joey D. Ocon, K. Pilario, A. A. Padama","doi":"10.1088/1361-651x/ad53ee","DOIUrl":"https://doi.org/10.1088/1361-651x/ad53ee","url":null,"abstract":"\u0000 This paper presents a feature-centric strategy for predicting adsorption energies of key CO2 reduction reaction (CO2RR) adsorbates, CO and H species, utilizing DFT-based calculations for eight (8) adsorption sites and considering alloying effects of nine (9) transition metals at single-atom concentrations. Here, we explore a class of materials consisting of a majority host metal where individual atoms of a different element are dispersed called single-atom alloys (SAA). A total of eight (8) feature selection methods are assessed within Gradient Boosting Regression and Linear Regression models. This study proposes a practical and effective two-stage approach that narrows down the initial 86 features to subsets of 10 and 7 for CO and H adsorption energy predictions, respectively, with the arithmetic mean of valence electrons (VE-am) feature consistently emerging as highly influential, validated through permutation and Shapley additive explanations (SHAP)-based feature importance analyses. The models exhibit robust performance on unseen data, indicating their generalization capability. The findings emphasize VE-am as a potential key machine learning feature for CO2RR on SAA surfaces and underline the effectiveness of the feature-centric approach in understanding feature impacts in machine learning models for CO2RR on SAA systems. Additionally, while other features based on structural, electronic and elemental properties may not individually impact the model significantly, their collective contribution plays a vital role in achieving more accurate adsorption energy predictions.","PeriodicalId":18648,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141266886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-04DOI: 10.1088/1361-651x/ad53ed
Kefan Chen, Sungkwang Mun, M. Baskes, M. Horstemeyer, Bin Li
Galvanizing is an important industrial process to improve the corrosion resistance of advanced high strength steels (AHSSs) that are vital for automotive industries. During galvanizing, nanoscale intermetallic phases with complex crystal structures are formed at the interface between the steel substrate and the zinc overlay. To better understand the nanoscale structures and the interfacial properties between the intermetallics, in this work, we develop a second nearest neighbor (2NN) Fe-Al-Zn ternary Modified Embedded Atom Method (MEAM) potential to describe the crystal structures of the intermetallics, i.e., Fe3Al8, Fe4Zn9 and FeZn13 and to calculate the interfacial structure and energy between them. The developed MEAM potential describes well the complex crystal structures and can be used to investigate the interfacial properties that are difficult to obtain from experiments. The Fe4Zn9, FeZn13 surface energies; the Fe-Fe4Zn9, Fe-FeZn13, Fe3Al8-FeZn13 interfacial energies; and the work of adhesion (WOA) are calculated with the developed MEAM potential. The results show that FeZn13 crystal orientation has an insignificant effect on the FeZn13 surface energy and the Fe-FeZn13 interfacial energy. A negative interfacial energy is obtained for the Fe-Fe4Zn9 and the Fe-FeZn13 interface. The lowest interfacial energy is obtained in the {100}Fe case. The interfacial energy of Fe3Al8-FeZn13 depends on the surface termination of Fe3Al8 and FeZn13. A low interfacial energy is obtained when the surface termination of Fe3Al8 and FeZn13 are both Fe rich. In contrast, when the surface termination of Fe3Al8 is Al rich or the surface termination of FeZn13 is Zn rich, no low energy, stable interface can be formed between the two phases.
{"title":"Atomistic study of intermetallics of Fe-Al-Zn system and their interfacial properties","authors":"Kefan Chen, Sungkwang Mun, M. Baskes, M. Horstemeyer, Bin Li","doi":"10.1088/1361-651x/ad53ed","DOIUrl":"https://doi.org/10.1088/1361-651x/ad53ed","url":null,"abstract":"\u0000 Galvanizing is an important industrial process to improve the corrosion resistance of advanced high strength steels (AHSSs) that are vital for automotive industries. During galvanizing, nanoscale intermetallic phases with complex crystal structures are formed at the interface between the steel substrate and the zinc overlay. To better understand the nanoscale structures and the interfacial properties between the intermetallics, in this work, we develop a second nearest neighbor (2NN) Fe-Al-Zn ternary Modified Embedded Atom Method (MEAM) potential to describe the crystal structures of the intermetallics, i.e., Fe3Al8, Fe4Zn9 and FeZn13 and to calculate the interfacial structure and energy between them. The developed MEAM potential describes well the complex crystal structures and can be used to investigate the interfacial properties that are difficult to obtain from experiments. The Fe4Zn9, FeZn13 surface energies; the Fe-Fe4Zn9, Fe-FeZn13, Fe3Al8-FeZn13 interfacial energies; and the work of adhesion (WOA) are calculated with the developed MEAM potential. The results show that FeZn13 crystal orientation has an insignificant effect on the FeZn13 surface energy and the Fe-FeZn13 interfacial energy. A negative interfacial energy is obtained for the Fe-Fe4Zn9 and the Fe-FeZn13 interface. The lowest interfacial energy is obtained in the {100}Fe case. The interfacial energy of Fe3Al8-FeZn13 depends on the surface termination of Fe3Al8 and FeZn13. A low interfacial energy is obtained when the surface termination of Fe3Al8 and FeZn13 are both Fe rich. In contrast, when the surface termination of Fe3Al8 is Al rich or the surface termination of FeZn13 is Zn rich, no low energy, stable interface can be formed between the two phases.","PeriodicalId":18648,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141266505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-02DOI: 10.1088/1361-651x/ad4b4d
Shiqing Yang, Guoxing Liang, Yonggui Huang, Xinhui Hao, Jian Zhao and Ming Lv
The density functional theory calculations of the adsorption model of NiCl2, Ni, and Cl on the Fe surface, as well as interface electronic properties, provide theoretical guidance for improving the Ni electrodeposition process. The adsorption properties of these three species on the Fe (100) crystal surface at different coverages, and the adsorption properties of the single Ni on three different crystal surfaces of Fe (100), Fe (110), and Fe (111), were studied through calculations of adsorption energy, charge density, charge occupancy, and DOS. The results indicate that the H sites are the most favorable for the adsorption of Ni and Cl on the Fe (100) surface. T sites, B sites, and H sites are all potential adsorption sites for NiCl2. The order of adsorption strength is Ni > Cl > NiCl2. In response to changes in charge, the adsorption effect exhibits a negative correlation with surface coverage. In addition, the hybridization of Ni’s 3d orbitals, Cl’s 3p orbitals, and Fe’s 3d orbitals changes the distribution of the interface charge, resulting in an increase of the charge in the Fe surface. Ni exhibits better adsorption performance on Fe (100) surface, driven by the lattice structure, surface electron configuration, and Ni–Fe atomic interactions.
密度泛函理论计算了NiCl2、Ni和Cl在铁表面的吸附模型以及界面电子特性，为改进Ni电沉积工艺提供了理论指导。通过计算吸附能、电荷密度、电荷占位和 DOS，研究了这三种物质在不同覆盖度的 Fe (100) 晶面上的吸附特性，以及单个 Ni 在 Fe (100)、Fe (110) 和 Fe (111) 三种不同晶面上的吸附特性。结果表明，H 位点最有利于 Ni 和 Cl 在 Fe (100) 表面的吸附。T 位点、B 位点和 H 位点都是 NiCl2 的潜在吸附位点。吸附强度的顺序为 Ni > Cl > NiCl2。针对电荷的变化，吸附效应与表面覆盖率呈负相关。此外，Ni 的 3d 轨道、Cl 的 3p 轨道和 Fe 的 3d 轨道的杂化改变了界面电荷的分布，导致 Fe 表面的电荷增加。受晶格结构、表面电子构型和镍-铁原子相互作用的影响，镍在铁（100）表面表现出更好的吸附性能。
{"title":"Adsorption structure and properties of Ni/Fe electrodeposition interface: a DFT study","authors":"Shiqing Yang, Guoxing Liang, Yonggui Huang, Xinhui Hao, Jian Zhao and Ming Lv","doi":"10.1088/1361-651x/ad4b4d","DOIUrl":"https://doi.org/10.1088/1361-651x/ad4b4d","url":null,"abstract":"The density functional theory calculations of the adsorption model of NiCl2, Ni, and Cl on the Fe surface, as well as interface electronic properties, provide theoretical guidance for improving the Ni electrodeposition process. The adsorption properties of these three species on the Fe (100) crystal surface at different coverages, and the adsorption properties of the single Ni on three different crystal surfaces of Fe (100), Fe (110), and Fe (111), were studied through calculations of adsorption energy, charge density, charge occupancy, and DOS. The results indicate that the H sites are the most favorable for the adsorption of Ni and Cl on the Fe (100) surface. T sites, B sites, and H sites are all potential adsorption sites for NiCl2. The order of adsorption strength is Ni > Cl > NiCl2. In response to changes in charge, the adsorption effect exhibits a negative correlation with surface coverage. In addition, the hybridization of Ni’s 3d orbitals, Cl’s 3p orbitals, and Fe’s 3d orbitals changes the distribution of the interface charge, resulting in an increase of the charge in the Fe surface. Ni exhibits better adsorption performance on Fe (100) surface, driven by the lattice structure, surface electron configuration, and Ni–Fe atomic interactions.","PeriodicalId":18648,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141258603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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