Article
Nanoscience & Nanotechnology
Joseph Indeck, David Cereceda, Jason R. Mayeur, Kavan Hazeli
Summary: The use of machine learning techniques in mechanics and materials research can enhance the understanding of microstructure-property relationships. In this study, various machine learning techniques were employed to analyze mesoscopic deformation mechanisms and gain insights into void nucleation in polycrystalline metals. The results showed that unsupervised clustering analysis combined with a K-nearest neighbor classifier accurately characterized slip transmission and identified grains with fatigue-induced voids. It was also discovered that the inclusion of partially-active slip systems was more appropriate for predicting slip activity than the binary classification. The study concluded that grains containing fatigue-induced voids were more likely to be surrounded by grains with orientations that inhibited slip transmission according to the Lee Robertson-Birnbaum criteria. Furthermore, it was demonstrated that smaller datasets using limited simulation results could yield similar outcomes when additional physical descriptors for the slip system activity were incorporated.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Metallurgy & Metallurgical Engineering
Xianyun Zhu, Yuqian Wang, Luiz Carneiro, Huamiao Wang, Yanyao Jiang
Summary: Comprehensive experiments were conducted on a rolled AZ31B Mg thick plate and a tubular specimen to evaluate the elastic-viscoplastic self-consistent model with twinning and detwinning (EVPSC-TDT) on magnesium alloys. The model accurately predicted stress-strain curves, hardening rates, textures after fracture, and tension twin evolutions for different loading conditions. The experiment also observed the Swift effect, which was properly simulated by the model.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Article
Materials Science, Multidisciplinary
L. Lapostolle, L. Morin, K. Derrien, L. Berthe, O. Castelnau
Summary: We investigate the influence of material microstructure on plastic strain and residual stress fields in elasto-plastic shockwaves induced by high power laser impacts in 2D polycrystalline metallic alloys. Simulations on single crystal specimens with different lattice orientations show that plastic strain is concentrated in narrow bands at the edges of the laser impact and parallel to the slip planes. For polycrystalline microstructures composed of randomly oriented grains, the random morphology results in a heterogeneous distribution of residual plastic strain and stress fields, which deviates from the commonly modeled residual stress fields. Statistical analysis of mechanical fields over a large number of microstructures reveals that localized concentrations of less compressive or tensile residual stresses at the surface may reduce the fatigue resistance of the shocked material.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Behnam Ahmadikia, Leyun Wang, M. Arul Kumar, Irene J. Beyerlein
Summary: By using mechanical testing, scanning electron microscopy, and a unified crystal plasticity framework, this study examines the intense and localized slip bands on prismatic planes and {1012} 1011 tensile twins in commercially pure titanium, as well as their transmission across grain boundaries. The results demonstrate that the orientation and curvature of the grain boundaries significantly affect the local stress fields and consequently the transmission of slip/twin. The neighboring grain properties, including active slip systems, slip bands, and twins, also play a crucial role in the deformation mechanisms.
Article
Materials Science, Multidisciplinary
Krishna Yaddanapudi, Brandon Leu, M. Arul Kumar, Xin Wang, Julie M. Schoenung, Enrique J. Lavernia, Timothy J. Rupert, Irene J. Beyerlein, Subhash Mahajan
Summary: This study investigated {(1) over bar 012} tensile twins terminating inside the grains of a deformed Mg-Y alloy using transmission electron microscopy. Crystallographic features of the terminating twins and associated slip structures were quantified and analyzed, with local stresses computed using crystal plasticity simulations. Basal < a > and < c + a > matrix glide were found to accommodate the plastic stresses near the terminating twins, with defect contrast consistent with lattice dislocations and twinning partials observed along the twin boundary. A dislocation reaction was proposed to establish the interrelationship between matrix glide and {(1) over bar 012} twinning in Mg-Y alloys.
Article
Chemistry, Physical
Chaitanya Paramatmuni, Anil Bandi, Anand K. Kanjarla
Summary: The ductility of Magnesium alloys is often limited by the strong basal texture. Previous attempts to reduce the intensity of basal textures involved adding rare earth (RE) elements. However, due to cost and scarcity, alloys with calcium and tin have recently been introduced. Among them, Mg-2Sn-2Ca alloys have shown high strength in extruded condition. This study reports the mechanical properties of the alloy in sheet form for the first time, examining in-plane mechanical anisotropy, texture, microstructure, and deformation twins.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Multidisciplinary Sciences
Thomasina V. Ball, Neil J. Balmforth
Summary: An asymptotic model is constructed to describe the bending of thin sheets of viscoplastic fluid, incorporating the von Mises yield condition and a nonlinear viscous stress. The model reduces to previous models from plasticity theory and viscous fluid mechanics in various limits, and it is characterized by a yield criterion proposed by Ilyushin. The model is used to explore the bending behavior of loaded flat plates, impulsive-driven circular plates, and tension-controlled deflection of loaded beams.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Nanoscience & Nanotechnology
Bohan Wang, Takumi Kimura, Tomotaka Miyazawa, Shigeo Arai, Toshiyuki Fujii
Summary: Metallic structures are prone to fatigue-related failure due to damage caused by dislocation structures. Investigation of dislocation structures is important for understanding the fatigue process. This study analyzed the formation mechanism of dislocation structures in [111] single crystal copper and their relationship with fatigue behavior under different plastic shear strain amplitudes. The results showed the development of vein-like and wall structures and the formation of deformation and cell bands. The cell band development had a significant impact on the cyclic softening of the single crystal copper, with a positive linear relationship existing between shear stress amplitude and reciprocal of cell width.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Review
Chemistry, Physical
Qilong Feng, Chongzhi Zhu, Guan Sheng, Tulai Sun, Yonghe Li, Yihan Zhu
Summary: The resolution of scanning transmission electron microscopy (STEM) has reached atomic level, providing promising prospects for microscale characterization in various fields. However, the traditional STEM detector is limited in its detection mechanism, leading to the loss of angle-resolved information and reduced efficiency. To address this issue, the development of four-dimensional STEM (4D-STEM) technology, with advances in electron direct detection techniques and detectors, offers high-throughput and high-dose efficiency imaging.
ACTA PHYSICO-CHIMICA SINICA
(2023)
Article
Chemistry, Multidisciplinary
Benjamin P. A. Gabriele, Craig J. Williams, Matthias E. Lauer, Brian Derby, Aurora J. Cruz-Cabeza
Summary: Nanoindentation measurements and atomic force microscopy imaging revealed the mechanical properties and surface characteristics of different crystal faces of CBZ form III, showing anisotropic stiffness and molecular flexibility leading to unique behaviors during indentation. Molecular dynamics simulations further confirmed the primary slip plane and the role of hydrogen bonding in the material's mechanical response on the (020) face.
Article
Nanoscience & Nanotechnology
Penghui Zhang, Weidong Zeng, Runchen Jia, Yinze Kou, Jianwei Xu, Xiaobo Liang, Yongqing Zhao
Summary: In this study, the tensile behavior and deformation mechanism of two microstructures for Ti-22Al-25Nb alloy were investigated using in-situ tensile test and electron backscatter diffraction (EBSD) experiment. The solution-treated microstructure exhibited better plasticity due to higher B2 phase content, while the aged microstructure showed higher strength with short and scattered slip lines due to obstruction from acicular O phase. Various slip modes for both B2 and O phases were identified, and there was good slip transmission between the two phases facilitated by the Burgers orientation relation (BOR).
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Mechanical
Meijuan Zhang, K. Nguyen, Javier Segurado, Francisco J. Montans
Summary: The purpose of continuum plasticity models and crystal plasticity models is to predict the behavior and design the material effectively. Although there are significant differences in the computational frameworks between the two approaches, the new formulation for crystal plasticity is parallel in structure to continuum plasticity, preserving its attractive aspects.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Engineering, Mechanical
Gaoming Zhu, Leyun Wang, Yingjun Sun, Xiaoqing Shang, Jie Wang, Huamiao Wang, Xiaoqin Zeng
Summary: Grain refinement in Mg-3Al-3Sn alloy can increase yield strength while decreasing strain hardening exponent, with different slip modes being affected by the grain size. A model taking grain size into account successfully predicts the deformation behavior, showing that prismatic slip is the dominant mode in this alloy and coarse-grained samples exhibit higher dislocation nucleation coefficient due to twin formation.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Chemistry, Physical
Sanket Chougale, Dirk Romeis, Marina Saphiannikova
Summary: Magnetoactive elastomers (MAEs) have attracted significant attention due to their wide engineering applications. This paper investigates the interplay between particle microstructure and sample shape in MAEs. By considering smeared microstructures, the study derives a simple analytical expression to describe the particle distribution, revealing that the enhancement of elastic moduli in MAEs comes from both induced dipole-dipole interactions and changes in particle microstructure.
Article
Engineering, Mechanical
Iftekhar A. Riyad, Brandon A. McWilliams, Brahmananda Pramanik, Marko Knezevic
Summary: This paper presents a multi-level viscoplastic self-consistent (VPSC) model for correlated structures (CS-VPSC). The model considers the response of inclusions, which can be either a single grain or a correlated structure of multiple single crystals. The model also accounts for factors such as strain rate, dislocation density, and slip transfer between adjacent correlated structures. The model is coupled with implicit finite element analysis (FE-CS-VPSC) and is used to predict the mechanical response and microstructural evolution of additively manufactured Ti-6Al-4 V (Ti64) alloy under different conditions. The predictions of the model align well with experimental data, allowing for discussions on various factors affecting the mechanical behavior.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Engineering, Mechanical
M. Wronski, M. Arul Kumar, R. J. McCabe, K. Wierzbanowski, C. N. Tome
Summary: The deformation behavior of commercially pure rolled titanium under strain path changes was studied using experiments and a crystal plasticity model, considering different loading combinations to investigate slip, twinning, de-twinning, and double-twinning in hexagonal closed packed titanium. An EBSD-based analysis was used to study the evolution of {1012} tensile and {1122} compression twins, supporting the model results. The VPSC model successfully predicted the evolution of twinning and twin volume fraction under strain path changes, with results in agreement with experimental observations.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Engineering, Mechanical
Nathan Bieberdorf, Aaron Tallman, M. Arul Kumar, Vincent Taupin, Ricardo A. Lebensohn, Laurent Capolungo
Summary: In this study, a physics-based crystal plasticity model was developed to predict failure in Grade 91 steel. A material response database and a new reduced-order lifetime predictor were generated, and the proposed lifetime assessment tool predicted rupture times several orders more conservative compared to current empirically derived lifetime relations.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Materials Science, Multidisciplinary
M. Arul Kumar, K. Dang, V. Taupin, R. J. McCabe, C. N. Tome, L. Capolungo
Summary: This study investigates the effect of twinned grain boundary characteristics on twin transmission in magnesium. The research finds that twin transmission propensity decreases with increasing misorientation angle across the grain boundary and is more favorable along the lateral direction. The observed twin transmission configurations in actual material do not correspond to the commonly considered tilt or twist grain boundaries.
Article
Materials Science, Multidisciplinary
Brandon Leu, M. Arul Kumar, Kelvin Y. Xie, Irene J. Beyerlein
Summary: The study reveals that the interactions between precipitates and deformation twins in magnesium alloys can influence the propagation and formation of twins, with various pathways suggested depending on the location of interaction site and thickness of the precipitate.
Article
Materials Science, Multidisciplinary
Brandon Leu, M. Arul Kumar, Paul F. Rottmann, Kevin J. Hemker, Irene J. Beyerlein
Summary: Understanding and controlling the development of deformation twins is crucial for engineering strong and stable hexagonal close-packed (HCP) Mg alloys. This study investigates the elastic strains and stresses around irregular twins using experimental and computational methods, providing insights into the mechanisms of twin development and the microstructural features that influence it.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Materials Science, Multidisciplinary
J. R. Jessy Michla, B. Ravikumar, T. Ram Prabhu, Suchart Siengchin, M. Arul Kumar, N. Rajini
Summary: The effect of nitriding process on the microstructure and mechanical properties of additively manufactured 17-4PH stainless steel is investigated. The nitriding process improves the hardness and surface roughness of the steel, leading to the development of almost equiaxed grain microstructure and the introduction of new precipitates.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
G. Elizabeth Rani, R. Murugeswari, Suchart Siengchin, N. Rajini, M. Arul Kumar
Summary: This work develops an automated image analysis tool for establishing quantitative correlations between particle/cluster size distribution and mechanical properties of particle reinforced polymer composites (PRPC). The tool, developed within Python programming software, processes and analyzes microstructural images of polymer-based composites. Statistical analysis reveals the presence of clustering of clusters in addition to the common clustering of particles, and a bimodal distribution of particles/clusters. An effective volume fraction is proposed to capture the agglomeration effect, and the standard rule-of-mixture model accurately predicts the tensile strength and modulus based on filler wt.%. The applicability of the effective volume fraction to other theoretical models is also analyzed. This detailed statistical analysis and proposed effective volume fraction contribute to a deeper quantitative understanding of PRPC compared to conventional qualitative correlations with microstructural features and properties and failure processes.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
Brandon Leu, M. Arul Kumar, Kelvin Xie, Irene J. Beyerlein
Summary: A two-step growth mechanism for {101over line 2} tensile twins blocked by basal-precipitates in precipitate-hardened AZ91 magnesium alloy is proposed based on an elasto-viscoplastic fast-Fourier-transform (EVP-FFT) model. The stress fields resulting from the interaction of two sequentially propagated twins with a precipitate promote twin growth at the twin-precipitate junction. This mechanism explains the existence of thick twin domains in these material systems despite the hindrance of twin growth in precipitate-hardened Mg alloys.
Article
Engineering, Mechanical
Mariyappan Arul Kumar, Laurent Capolungo
Summary: Predicting the effects of microstructure on high-temperature creep responses of steel components is critical to minimize the risks of failure and maximize economic viability in the energy sector. In this study, an advanced mechanistic constitutive model is used to investigate the influence of microstructure on creep responses and to explain the variability in the performance of grade-91 alloy. The model accurately predicts steady-state creep rates and primary-to-secondary transients for a wide range of creep conditions, and can also extrapolate the creep response of grade-91 alloy outside of the calibration regime. The study shows that the initial microstructure, characterized by grain size, dislocation density, and precipitate content, plays a significant role in the creep response, with the significance varying with stress and temperature. Comparing the model predictions with experimental data reveals that the differences in creep responses can be rationalized based on differences in the initial microstructure.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Materials Science, Multidisciplinary
Behnam Ahmadikia, Leyun Wang, M. Arul Kumar, Irene J. Beyerlein
Summary: By using mechanical testing, scanning electron microscopy, and a unified crystal plasticity framework, this study examines the intense and localized slip bands on prismatic planes and {1012} 1011 tensile twins in commercially pure titanium, as well as their transmission across grain boundaries. The results demonstrate that the orientation and curvature of the grain boundaries significantly affect the local stress fields and consequently the transmission of slip/twin. The neighboring grain properties, including active slip systems, slip bands, and twins, also play a crucial role in the deformation mechanisms.
Article
Chemistry, Physical
Jiaxiang Wang, Mariyappan Arul Kumar, Irene J. Beyerlein
Summary: This work investigates the effect of alloying addition on the transformation of twin-twin interactions into crossed-twin structures in magnesium alloys. The study reveals the influence of plastic anisotropy and alloying elements on the formation of crossed twin structures. It proposes that the proper choice of alloying elements can hinder the formation of crossed twin structures and improve the ductility of magnesium alloys.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Crystallography
Mariyappan Arul Kumar, Marcin Wronski, Irene J. Beyerlein
Summary: Hexagonal close-packed (HCP) magnesium alloys are widely used in automotive and aerospace industries due to their low density and high specific-strength. However, their poor formability and pronounced plastic anisotropy limit their applicability. This work proposes that the formability of Mg alloys can be improved by combining grain refinement and alloying approaches. A crystal-plasticity-based constitutive model is developed to quantitively explore this possibility and identify the optimal microstructure and chemistry for desired Mg alloy performance.
Article
Metallurgy & Metallurgical Engineering
Krishna Yaddanapudi, Mariyappan Arul Kumar, Jiaxiang Wang, Xin Wang, Timothy J. Rupert, Enrique J. Lavernia, Julie M. Schoenung, Irene J. Beyerlein, Subhash Mahajan
Summary: This study investigates the effects of twin-twin interactions on the distribution of defects and stress fields in a magnesium alloy. The analysis focuses on a specific twin junction in a deformed Mg-3wt.%Y alloy. The results show that the morphology of the twins is asymmetric and the dislocations concentrate near the twin-twin junction site. Crystal plasticity calculations suggest that the local stress fields generated at the junction site are responsible for the observed concentration of dislocations. These findings provide insights into the twinning behavior and mechanical properties of Mg alloys.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Article
Materials Science, Multidisciplinary
Mariyappan Arul Kumar, Rodney McCabe, Carlos Tome, Laurent Capolungo
Summary: This study critically analyzes the geometric compatibility factor m' for twin transmission across grain boundaries (GBs), and finds that m' cannot accurately describe and predict twin transmission events. The applicability of m' is influenced by the elastic anisotropy, plastic anisotropy, and strain levels. Local stresses play a dominant role in twin transmission compared to geometric alignment.
MATERIALS TODAY COMMUNICATIONS
(2022)
