Pub Date : 2024-01-23DOI: 10.1088/1361-651x/ad2188
Thi-Thuy Binh Ngo, Van-Thuc Nguyen, Te-Hua Fang
The mechanical properties and deformation behavior of CoCrNiAl medium entropy alloy (MEA) subjected to indentation by an indenter tooltip on the substrate are explored using molecular dynamics (MD) simulation. The study investigates the effects of alloy compositions, temperature variations, and ultra vibration (UV) on parameters, such as total force, shear strain, shear stress, hardness, reduced modulus, substrate temperature, phase transformation, dislocation length, and elastic recovery. The findings indicate that higher alloy compositions result in increased total force, hardness, and reduced modulus, with Ni-rich compositions demonstrating superior mechanical strength. Conversely, increasing alloy compositions lead to reduced von Mises stress (VMS), phase transformation, dislocation distribution, and dislocation length due to the larger atomic size of Ni compared to other primary elements. At elevated substrate temperatures, atoms exhibit larger vibration amplitudes and interatomic separations, leading to weaker atomic bonding and decreased contact force, rendering the substrate softer at higher temperatures. Additionally, higher initial substrate temperatures enhance atom kinetic energy and thermal vibrations, leading to reduced material hardness and increased VMS levels. Increasing vibration frequency enlarges the indentation area on the substrate's surface, concentrating shear strain and VMS with vibration frequency. Higher vibration amplitude and frequency amplify force, shear strain, VMS, substrate temperature, and dislocation distribution. Conversely, lower vibration amplitude and frequency result in a smaller average elastic recovery ratio. Moreover, increased amplitude and frequency values yield an amorphous-dominated indentation region and increased proportions of HCP and BCC structures. Furthermore, this study also takes into account the evaluation of a material's ability to recover elastically during the indentation process, which is a fundamental material property.
{"title":"Study of nanoindentation behavior of NiCrCoAl medium entropy alloys under indentation process using molecular dynamics","authors":"Thi-Thuy Binh Ngo, Van-Thuc Nguyen, Te-Hua Fang","doi":"10.1088/1361-651x/ad2188","DOIUrl":"https://doi.org/10.1088/1361-651x/ad2188","url":null,"abstract":"\u0000 The mechanical properties and deformation behavior of CoCrNiAl medium entropy alloy (MEA) subjected to indentation by an indenter tooltip on the substrate are explored using molecular dynamics (MD) simulation. The study investigates the effects of alloy compositions, temperature variations, and ultra vibration (UV) on parameters, such as total force, shear strain, shear stress, hardness, reduced modulus, substrate temperature, phase transformation, dislocation length, and elastic recovery. The findings indicate that higher alloy compositions result in increased total force, hardness, and reduced modulus, with Ni-rich compositions demonstrating superior mechanical strength. Conversely, increasing alloy compositions lead to reduced von Mises stress (VMS), phase transformation, dislocation distribution, and dislocation length due to the larger atomic size of Ni compared to other primary elements. At elevated substrate temperatures, atoms exhibit larger vibration amplitudes and interatomic separations, leading to weaker atomic bonding and decreased contact force, rendering the substrate softer at higher temperatures. Additionally, higher initial substrate temperatures enhance atom kinetic energy and thermal vibrations, leading to reduced material hardness and increased VMS levels. Increasing vibration frequency enlarges the indentation area on the substrate's surface, concentrating shear strain and VMS with vibration frequency. Higher vibration amplitude and frequency amplify force, shear strain, VMS, substrate temperature, and dislocation distribution. Conversely, lower vibration amplitude and frequency result in a smaller average elastic recovery ratio. Moreover, increased amplitude and frequency values yield an amorphous-dominated indentation region and increased proportions of HCP and BCC structures. Furthermore, this study also takes into account the evaluation of a material's ability to recover elastically during the indentation process, which is a fundamental material property.","PeriodicalId":503047,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":"103 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139605894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.1088/1361-651x/ad200b
S. T. Tanu Halim, Eugene - Ng
Understanding the effects of martensite volume fractions (Vm) in dual-phase (DP) steel resulting from heat treatment is crucial for designing structures for mechanical impact resistance and optimizing manufacturing processes. DP steel's material behaviour depends heavily on its microstructure properties. While stress-strain curves for individual phases in DP steels are often determined using empirical models, extensive experimental data is required to establish empirical model constants. This research aims to achieve two main objectives: Firstly, to calibrate stress-strain curves for pure ferrite and pure martensite using limited experimental data using Micromechanical Adaptive Iteration Algorithm (MAIA). This calibration involves using stress-strain data from DP steels with varying Vm during the calibration stage and additional data for verification. Secondly, to conduct a comprehensive sensitivity analysis of MAIA to assess its capabilities and limitations. Microstructure-based finite element (FE) models, simulated with ABAQUS/Standard, are employed to predict stress-strain curves under uniaxial tensile test conditions. The MAIA approach successfully calculated ferrite and martensite stress-strain curves that could predict plastic behaviour of DP steel with different Vm, which agreed with experimental work. Key advantages of this approach include avoiding complex 3D microstructure geometries and requiring only two experimentally obtained stress-strain curves with different Vm for material constant calibration, along with another curve for validation. However, the experimental data selected for calibration must have a Vm difference between 20% to 50% and one of the DP steels must have a low martensite volume fraction. The FE micromechanical model could capture the effect of softening of martensite phase and strengthening of ferrite phase as compared to its bulk properties for DP steel. The effect of Vm on strain hardening rate was also successfully captured. This technique comes with obvious shortcomings, such as excluding crystal plasticity behaviour, and change in chemical composition within the individual phase with varying martensite volume fraction.
了解热处理后双相钢（DP）中马氏体体积分数（Vm）的影响，对于设计抗机械冲击结构和优化制造工艺至关重要。DP 钢的材料性能在很大程度上取决于其微观结构特性。虽然 DP 钢中各相的应力-应变曲线通常使用经验模型确定，但需要大量实验数据来建立经验模型常数。本研究旨在实现两个主要目标：首先，使用微机械自适应迭代算法（MAIA），利用有限的实验数据校准纯铁素体和纯马氏体的应力-应变曲线。校准过程包括在校准阶段使用不同 Vm 的 DP 钢的应力应变数据，以及用于验证的其他数据。其次，对 MAIA 进行全面的敏感性分析，以评估其能力和局限性。使用 ABAQUS/Standard 模拟基于微结构的有限元 (FE) 模型，预测单轴拉伸试验条件下的应力-应变曲线。MAIA 方法成功计算了铁素体和马氏体应力-应变曲线，可以预测不同 Vm 的 DP 钢的塑性行为，这与实验结果一致。这种方法的主要优点包括：避免了复杂的三维微观结构几何形状，只需要两条实验获得的不同 Vm 的应力-应变曲线进行材料常数校准，以及另一条曲线进行验证。不过，选定用于校准的实验数据的 Vm 值必须相差 20% 至 50%，其中一种 DP 钢的马氏体体积分数必须较低。与 DP 钢的整体性能相比，有限元微观力学模型可以捕捉到马氏体相软化和铁素体相强化的影响。此外，还成功捕捉到了 Vm 对应变硬化率的影响。这种技术存在明显的缺陷，例如不包括晶体塑性行为，以及随着马氏体体积分数的变化，各相内部化学成分的变化。
{"title":"A Unique Numerical Iterative Approach for Modelling Individual Phase Stress-Strain Curves in Dual Phase Steel","authors":"S. T. Tanu Halim, Eugene - Ng","doi":"10.1088/1361-651x/ad200b","DOIUrl":"https://doi.org/10.1088/1361-651x/ad200b","url":null,"abstract":"\u0000 Understanding the effects of martensite volume fractions (Vm) in dual-phase (DP) steel resulting from heat treatment is crucial for designing structures for mechanical impact resistance and optimizing manufacturing processes. DP steel's material behaviour depends heavily on its microstructure properties. While stress-strain curves for individual phases in DP steels are often determined using empirical models, extensive experimental data is required to establish empirical model constants. This research aims to achieve two main objectives: Firstly, to calibrate stress-strain curves for pure ferrite and pure martensite using limited experimental data using Micromechanical Adaptive Iteration Algorithm (MAIA). This calibration involves using stress-strain data from DP steels with varying Vm during the calibration stage and additional data for verification. Secondly, to conduct a comprehensive sensitivity analysis of MAIA to assess its capabilities and limitations. Microstructure-based finite element (FE) models, simulated with ABAQUS/Standard, are employed to predict stress-strain curves under uniaxial tensile test conditions. The MAIA approach successfully calculated ferrite and martensite stress-strain curves that could predict plastic behaviour of DP steel with different Vm, which agreed with experimental work. Key advantages of this approach include avoiding complex 3D microstructure geometries and requiring only two experimentally obtained stress-strain curves with different Vm for material constant calibration, along with another curve for validation. However, the experimental data selected for calibration must have a Vm difference between 20% to 50% and one of the DP steels must have a low martensite volume fraction. The FE micromechanical model could capture the effect of softening of martensite phase and strengthening of ferrite phase as compared to its bulk properties for DP steel. The effect of Vm on strain hardening rate was also successfully captured. This technique comes with obvious shortcomings, such as excluding crystal plasticity behaviour, and change in chemical composition within the individual phase with varying martensite volume fraction.","PeriodicalId":503047,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":"125 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139615903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-16DOI: 10.1088/1361-651x/ad1f48
M. Younis, M. Yousaf, Toheed Akhter, Mubashar Ali, Junaid Munir
The study demonstrates layer-sliding-mediated controlled interfacial engineering to induce multifunctionality into a van der Waals heterostructure (vdWHS), consisting of two-dimensional (2D) silicene and hexagonal boron nitride (hBN). To manifest the aforementioned strategy, silicene is slided over hBN, and the resulting variations in the physical properties such as interfacial electronic and optical properties of vdWHS are analyzed. A nifty modeling of vdWHS, not only identifies the most stable stacking pattern but also minimizes the lattice mismatch between silicene and hBN to 2.97%. After obtaining the most optimal stacking configuration of vdWHS, the position of potassium (K) intercalant at the interface is screened out. Various physical parameters such as binding energy, vdW-gap and buckling distance (ΔZ) relating to the intercalated system are computed repeatedly along the sliding pathway. The stability of the various K-intercalated stacking patterns is verified by calculating and comparing the total energies with and without vdW contributions. Upon completion of the sliding, calculated vdW-gap with and without vdW contributions increases by 2.7 and 5.6%, respectively. The highest energy barrier encountered throughout the sliding pathway with (without) vdW contributions is 0.84 (0.72) eV. Planar average charge density difference, charge transfer, and interface dipole moment are calculated and analyzed to investigate the variation in interfacial electronic properties resulting from layer-sliding and intercalation. A notable increase (5.86%) in charge transfer from hBN to silicene is seen upon completion of the layer-sliding. Several optical properties associated with the intercalated vdWHS such as real [varepsilon_1left(omegaright)] and imaginary [varepsilon_2left(omegaright)] parts of the complex dielectric function (DF), electron energy loss function [Lleft(omegaright)], diagonal components of the dielectric tensor [varepsilonleft(iomegaright)] and optical joint density of states left[Jleft(omegaright)right] have been examined. Polarizability of un-slided vdWHS is changed significantly due to the layer-sliding, with a reduction of 24.85 and 6.76% for the midway and fully-slided configurations, respectively. Sliding process results in an increase in the optical absorption in the UV region by 23.14 and 44.18% for the midway and fully-slided configurations as compared with the un-slided vdWHS. Plots relating to Jleft(omegaright) indicate that the most probable optical transitions occur at 7.50, 7.66, and 7.43 eV for the initial, middle, and fully-slided configurations, respectively. The suggested layer-sliding technique has a potential to introduce multifunctionality in 2D materials by varying the properties in a controllable and reversible manner.
{"title":"Realization of controllable multifunctionality by interfacial engineering: The case of silicene/hBN van der Waals heterostructure","authors":"M. Younis, M. Yousaf, Toheed Akhter, Mubashar Ali, Junaid Munir","doi":"10.1088/1361-651x/ad1f48","DOIUrl":"https://doi.org/10.1088/1361-651x/ad1f48","url":null,"abstract":"\u0000 The study demonstrates layer-sliding-mediated controlled interfacial engineering to induce multifunctionality into a van der Waals heterostructure (vdWHS), consisting of two-dimensional (2D) silicene and hexagonal boron nitride (hBN). To manifest the aforementioned strategy, silicene is slided over hBN, and the resulting variations in the physical properties such as interfacial electronic and optical properties of vdWHS are analyzed. A nifty modeling of vdWHS, not only identifies the most stable stacking pattern but also minimizes the lattice mismatch between silicene and hBN to 2.97%. After obtaining the most optimal stacking configuration of vdWHS, the position of potassium (K) intercalant at the interface is screened out. Various physical parameters such as binding energy, vdW-gap and buckling distance (ΔZ) relating to the intercalated system are computed repeatedly along the sliding pathway. The stability of the various K-intercalated stacking patterns is verified by calculating and comparing the total energies with and without vdW contributions. Upon completion of the sliding, calculated vdW-gap with and without vdW contributions increases by 2.7 and 5.6%, respectively. The highest energy barrier encountered throughout the sliding pathway with (without) vdW contributions is 0.84 (0.72) eV. Planar average charge density difference, charge transfer, and interface dipole moment are calculated and analyzed to investigate the variation in interfacial electronic properties resulting from layer-sliding and intercalation. A notable increase (5.86%) in charge transfer from hBN to silicene is seen upon completion of the layer-sliding. Several optical properties associated with the intercalated vdWHS such as real [varepsilon_1left(omegaright)] and imaginary [varepsilon_2left(omegaright)] parts of the complex dielectric function (DF), electron energy loss function [Lleft(omegaright)], diagonal components of the dielectric tensor [varepsilonleft(iomegaright)] and optical joint density of states left[Jleft(omegaright)right] have been examined. Polarizability of un-slided vdWHS is changed significantly due to the layer-sliding, with a reduction of 24.85 and 6.76% for the midway and fully-slided configurations, respectively. Sliding process results in an increase in the optical absorption in the UV region by 23.14 and 44.18% for the midway and fully-slided configurations as compared with the un-slided vdWHS. Plots relating to Jleft(omegaright) indicate that the most probable optical transitions occur at 7.50, 7.66, and 7.43 eV for the initial, middle, and fully-slided configurations, respectively. The suggested layer-sliding technique has a potential to introduce multifunctionality in 2D materials by varying the properties in a controllable and reversible manner.","PeriodicalId":503047,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":" 31","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139619287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-16DOI: 10.1088/1361-651x/ad1f47
Jason Sun, Joseph J. Marziale, Amberkee S Haselhuhn, David Salac, James Chen
A manufacturing-driven ICME framework is proposed to model short fiber reinforced ceramic matrix composite via direct ink writing. Currently, there lacks efforts to investigate the effects of properties of short fiber reinforced ceramic matrix composites due to fiber alignment variance. A multi-scale modeling approach is presented to use representative volume elements to capture the homogenized mechanical behavior at various fiber aspect ratio and volume ratio. The orthotropic material properties are mapped to model the printing process. A series of tensile tests simulations show that with 20$^circ$ standard deviation in fiber alignment, the fracture plane has the maximum local tensile stress range at 30 degree printing angle. This local tensile stress variation is shown the minimum at 90 degree When the standard deviation increases from 20 degree to 40 degree, the average tensile strength across the fracture plane decreases by 2%, but the stress variations increase 27.6%.
{"title":"An ICME Framework for Short Fiber Reinforced Ceramic Matrix Composites via Direct Ink Writing","authors":"Jason Sun, Joseph J. Marziale, Amberkee S Haselhuhn, David Salac, James Chen","doi":"10.1088/1361-651x/ad1f47","DOIUrl":"https://doi.org/10.1088/1361-651x/ad1f47","url":null,"abstract":"\u0000 A manufacturing-driven ICME framework is proposed to model short fiber reinforced ceramic matrix composite via direct ink writing. Currently, there lacks efforts to investigate the effects of properties of short fiber reinforced ceramic matrix composites due to fiber alignment variance. A multi-scale modeling approach is presented to use representative volume elements to capture the homogenized mechanical behavior at various fiber aspect ratio and volume ratio. The orthotropic material properties are mapped to model the printing process. A series of tensile tests simulations show that with 20$^circ$ standard deviation in fiber alignment, the fracture plane has the maximum local tensile stress range at 30 degree printing angle. This local tensile stress variation is shown the minimum at 90 degree When the standard deviation increases from 20 degree to 40 degree, the average tensile strength across the fracture plane decreases by 2%, but the stress variations increase 27.6%.","PeriodicalId":503047,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":" 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139620167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-16DOI: 10.1088/1361-651x/ad1f46
Xiaobin Liu, Chang Su, Qiuxia Huang, Shenghui Yang, Lei Zhang, Xiaolan Xie, Huanfu Zhou
Microwave dielectric ceramic (MWDC) is crucial in advancing the development of 5G technology and the communication field. The prediction or calculation of its properties is of great significance for accelerating the design and development of MWDCs. Therefore, the prediction of permittivity of spinel MWDCs based on machine learning was investigated in this work. Firstly, we collected 280 single-phase spinel MWDC entries and constructed feature engineering, which includes feature generation and feature selection (five dominant features, including Mpo, Dar, Mmbe, Aose and Dgnve, were selected from 208 generated features). Next, seven commonly used algorithms were utilized during the training process of machine learning models. The eXtreme Gradient Boosting (XGBoost) model shows the best performance with R-squared (R2) of 0.9095, Mean Absolute Error (MAE) of 1.02 and Root Mean Square Error (RMSE) of 1.96. Furthermore, all the machine learning models show enhanced prediction (calculation accuracy) of the permittivity of spinel MWDCs compared to the traditional Clausius-Mossotti (C-M) equation, which can provide a guide for the design and development of spinel MWDCs applied for wireless communication.
{"title":"Machine Learning Enhanced Prediction of Permittivity of Spinel Microwave Dielectric Ceramics Compared to Traditional C-M Calculation","authors":"Xiaobin Liu, Chang Su, Qiuxia Huang, Shenghui Yang, Lei Zhang, Xiaolan Xie, Huanfu Zhou","doi":"10.1088/1361-651x/ad1f46","DOIUrl":"https://doi.org/10.1088/1361-651x/ad1f46","url":null,"abstract":"\u0000 Microwave dielectric ceramic (MWDC) is crucial in advancing the development of 5G technology and the communication field. The prediction or calculation of its properties is of great significance for accelerating the design and development of MWDCs. Therefore, the prediction of permittivity of spinel MWDCs based on machine learning was investigated in this work. Firstly, we collected 280 single-phase spinel MWDC entries and constructed feature engineering, which includes feature generation and feature selection (five dominant features, including Mpo, Dar, Mmbe, Aose and Dgnve, were selected from 208 generated features). Next, seven commonly used algorithms were utilized during the training process of machine learning models. The eXtreme Gradient Boosting (XGBoost) model shows the best performance with R-squared (R2) of 0.9095, Mean Absolute Error (MAE) of 1.02 and Root Mean Square Error (RMSE) of 1.96. Furthermore, all the machine learning models show enhanced prediction (calculation accuracy) of the permittivity of spinel MWDCs compared to the traditional Clausius-Mossotti (C-M) equation, which can provide a guide for the design and development of spinel MWDCs applied for wireless communication.","PeriodicalId":503047,"journal":{"name":"Modelling and Simulation in Materials Science and Engineering","volume":" 32","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139619594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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