Article
Mechanics
Anssi Laukkanen, Sampo Uusikallio, Matti Lindroos, Tom Andersson, Jukka Komi, David Porter
Summary: Ferritic-austenitic duplex stainless steels are preferred for their good mechanical properties and corrosion resistance, with current research focusing on micro-scale analysis of cleavage fracture behavior to enhance cleavage resistance. Investigations suggest that the fraction and morphology of austenite play a critical role in improving fracture toughness.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Mathematics, Interdisciplinary Applications
Jannick Kuhn, Matti Schneider, Petra Sonnweber-Ribic, Thomas Boehlke
Summary: This work focuses on synthetic microstructure models of polycrystalline materials. A novel method is introduced to prescribe the orientations of individual grains based on tensorial Fourier coefficients. The proposed method allows for the determination of representative orientations for digital polycrystalline microstructures. The method is compared to established algorithms in terms of the material's linear elastic and non-linear plastic behavior.
COMPUTATIONAL MECHANICS
(2022)
Article
Engineering, Mechanical
Matthias Boenisch, Pere Barriobero-Vila, Pushkar Prakash Dhekne, Andreas Stark, Norbert Schell, Tamas Ungar, Guillermo Requena, Marc Seefeldt
Summary: This work investigates the tension-compression asymmetry (TCA) in metastable austenitic stainless steel (MASS) under uniaxial loading at different temperatures. The study reveals that martensitic transformations and dislocation slip are the dominant deformation mechanisms at 24℃ and 100℃, respectively. The TCA is influenced by grain rotation and driving force anisotropy for alpha' formation. Furthermore, the lattice strains show pronounced tension-compression asymmetry due to the volume change related to alpha' formation. The stress partitioning between austenite and martensites also differs in tension and compression.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Engineering, Manufacturing
Zhangxi Feng, Elizabeth M. Mamros, Jinjin Ha, Brad L. Kinsey, Marko Knezevic
Summary: This paper introduces a new method for designing and manufacturing stainless steels by intentionally deforming induced manipulation of constituent phases to achieve heterogeneous and hierarchical microstructures. The research uses an elasto-plastic self-consistent modeling framework, calibrated and validated with SS304L and SS316L datasets to guide the manufacturing process.
CIRP JOURNAL OF MANUFACTURING SCIENCE AND TECHNOLOGY
(2021)
Article
Nanoscience & Nanotechnology
Yong Li, Wei Li, Shilei Li, Na Min, Laizhu Jiang, Qinglong Zhou, Xuejun Jin
Summary: By regulating the thermomechanical processing parameters, a multi-phase heterostructured microstructure with higher yield strength than the coarse grained counterpart was achieved in this study, with in-depth investigation on microscopic load transfer.
SCRIPTA MATERIALIA
(2021)
Article
Engineering, Mechanical
Zhangxi Feng, Milovan Zecevic, Marko Knezevic
Summary: This paper formulates kinetics laws for stress-assisted and strain-induced austenite to martensite transformation within a crystal plasticity framework, enabling modeling of strain path sensitive elasto-plastic deformation of austenitic steels. The models take into account the evolution of crystallographic texture and directionality of deformation mechanisms in constituent phases, predicting the deformation behavior of metastable austenitic steels while incorporating a new numerical feature to model the epsilon-martensite morphology. Through calibrating with experimental data, the implementation successfully predicts stress-strain response, texture, and phase fractions of different phases.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Mechanics
Matti Lindroos, Matti Isakov, Anssi Laukkanen
Summary: The study presents a crystal plasticity model to analyze the microscale deformation of 301LN stainless steel, considering phase transformation and dislocation slip mechanisms. The model reveals the material's strain hardening and phase transformation characteristics under different strain rates and temperatures, showing good agreement with experimental findings.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
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
Chemistry, Physical
Abhishek Biswas, Dzhem Kurtulan, Timothy Ngeru, Abril Azocar Guzman, Stefanie Hanke, Alexander Hartmaier
Summary: This study focuses on investigating the mechanical behavior of low-nickel austenitic steel under high-pressure torsion fatigue (HPTF) loading, particularly the axial creep deformation observed in the experiment. The results show that a J2 plasticity model with an associated flow rule fails to describe the axial creep behavior, while a micromechanical model based on an empirical crystal plasticity law with kinematic hardening described by the Ohno-Wang rule can accurately match the HPTF experiments. Therefore, our findings confirm the versatility of crystal plasticity combined with microstructural models in describing the mechanical behavior of materials under reversing multiaxial loading situations.
Article
Materials Science, Multidisciplinary
Joseph R. Michael, Lucille A. Giannuzzi, M. Grace Burke, Xiang Li Zhong
Summary: The transformation of unstable austenite to ferrite or alpha' martensite in a 304 stainless steel casting alloy due to Xe+ or Ga+ ion exposure at room temperature was investigated. Both Ga+ and Xe+ ion irradiation resulted in the transformation, and the crystallographic orientation of the transformed area was consistent with established orientation relationships.
MICROSCOPY AND MICROANALYSIS
(2022)
Article
Engineering, Civil
E. Borzabadi Farahani, B. Sobhani Aragh, A. Sarhadi, D. Juhre
Summary: A fully thermomechanical coupled phase-field model is developed to investigate austenite-to-martensite phase transformation and crack initiation and propagation in pure austenitic microstructures. The model considers latent heat transfer, temperature dependency, fracture surface energy, and damage evolution. The results demonstrate the applicability of the model in predicting fracture mechanisms in a thermomechanical field. The study highlights the significant impact of temperature on phase transformation and crack growth.
THIN-WALLED STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
Hamidreza Kamali, Haibo Xie, Hongyun Bi, E. Chang, Haigang Xu, Haifeng Yu, Zhengyi Jiang, Azdiar A. Gazder
Summary: This study investigates the microstructure evolution of a metastable austenitic Cr-Mn-N stainless steel during 90o bending, focusing on deformation-induced martensitic transformation, void formation, and crack propagation. The analysis reveals stress-strain heterogeneity, with the inner and outer radii experiencing compressive and tensile stress states respectively. Voids are observed at both austenite/martensite and martensite/martensite interfaces, while cracks tend to propagate along intergranular parent austenite grain boundaries and between martensite child-child grains.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Engineering, Mechanical
Navyanth Kusampudi, Martin Diehl
Summary: This study proposes a generative machine learning model for identifying low-dimensional descriptors of microstructural features and establishing structure-property relationships. Based on this model, an integrated framework for microstructure characterization, reconstruction, and design is presented for heterogeneous materials with polycrystalline microstructures.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Materials Science, Multidisciplinary
Ehsan Norouzi, Reza Miresmaeili, Hamid Reza Shahverdi, Mohsen Askari-Paykani, Laura Maria Vergani
Summary: The effect of hydrogen on the phase transformation, deformation twins, and dislocation density of metastable stainless steel 304 was investigated. Hydrogen charging resulted in the formation of a large amount of alpha-martensite, a high density of deformation twins, and an increased dislocation density compared to the uncharged state. This caused a significant loss of ductility by 60% in the presence of hydrogen in metastable austenitic stainless steel. Alpha-martensite and twins were preferred sites for crack initiation and propagation, leading to increased susceptibility to hydrogen embrittlement.
Article
Nanoscience & Nanotechnology
Xilin Xiong, Jun He, Huihui Zhi, Stoichko Antonov, Cheng Zhang, Yong Zhong, Yanjing Su
Summary: Annealing treatment below austenite start transformation temperature can improve the mechanical properties of martensitic stainless steel by stabilizing retained austenite and increasing its elongation.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Manas Vijay Upadhyay, Jeremy Bleyer
Summary: A time-explicit Runge-Kutta discontinuous Galerkin finite element scheme is proposed for solving the dislocation transport initial boundary value problem in 3D. This scheme provides stable and accurate numerical solutions through a combination of spatial and temporal discretization. Parameter study and simulation results show that the proposed scheme is more robust and accurate compared to existing methods based on continuous Galerkin finite element or fast Fourier transform.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2022)
Review
Materials Science, Multidisciplinary
S. Lucarini, M. Upadhyay, J. Segurado
Summary: FFT methods have become a fundamental tool in computational micromechanics. This paper provides a comprehensive review of the mathematical aspects and various approaches of FFT methods in micromechanical simulations. The applications of FFT methods in different materials and problems showcase its versatility and potential. The limitations of the method are also analyzed, and the future of FFT approaches in micromechanics is discussed.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
C. Sofras, J. Capek, A. Arabi-Hashemi, C. Leinenbach, M. Frost, K. An, R. E. Loge, M. Strobl, E. Polatidis
Summary: This study investigates the manipulation of crystallographic texture in austenitic stainless steels using laser-powder bed fusion (L-PBF) to tailor their deformation behavior. By adjusting laser power and scanning speed, tailored crystallographic textures can be obtained. The influence of crystallographic texture on deformation behavior is demonstrated, and the asymmetry between tension and compression is discussed.
MATERIALS & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Matteo Busi, Efthymios Polatidis, Florencia Malamud, Winfried Kockelmann, Manuel Morgano, Anders Kaestner, Anton Tremsin, Nikola Kalentics, Roland Loge, Christian Leinenbach, Takenao Shinohara, Markus Strobl
Summary: In this study, neutron Bragg edge tomography was used to analyze stainless steel 316L additive manufacturing samples created by standard laser powder bed fusion and a novel three-dimensional laser shock peening technique. The research focused on analyzing the bulk density properties, mapping defects, obtaining strain maps, and describing crystallographic texture properties of the samples. The results showed that the shock peening treatment not only increased the bulk density of the samples but also created a significant compressive strain region.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
E. Polatidis, S. Shukla, J. Capek, S. Van Petegem, N. Casati, R. S. Mishra
Summary: The mechanical behavior of a metastable high entropy alloy (HEA) with composition Fe39-Mn20-Co20-Cr15-Si5-1Al at% was investigated, and the deformation mechanisms contributing to its mechanical properties were revealed using in situ uniaxial tensile tests with synchrotron X-ray diffraction. Three distinct deformation regimes were observed, including an initial elastic regime, a dislocation-based plasticity regime, and a phase transformation regime. The phase transformation was accompanied by the formation of hexagonal close-packed (hcp) martensite and slip in the parent austenitic phase, as well as twinning in unfavorably oriented grains.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Automation & Control Systems
Sachin Bhardwaj, R. M. Chandima Ratnayake, Efthymios Polatidis, Jan Capek
Summary: This study investigated the residual stresses on girth welds fabricated at proximity using neutron diffraction. The findings revealed that the residual axial stresses at a 5-mm proximity distance were greater than the yield strength of the structural steel, grade S355. These findings provide technical justification for minimizing residual stresses and developing welding procedures for welds fabricated at proximity.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Jakob Schroder, Alexander Evans, Efthymios Polatidis, Gunther Mohr, Itziar Serrano-Munoz, Giovanni Bruno, Jan Capek
Summary: The manufacturability of metallic alloys using laser-based additive manufacturing methods has improved significantly in the past decade. However, the microstructures of these alloys, caused by local melting and solidification, possess hierarchical structures and crystallographic textures that result in mechanical anisotropy and pose challenges for diffraction-based residual stress determination.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Instruments & Instrumentation
S. Gaudez, M. Ben Haj Slama, A. Kaestner, M. Upadhyay
Summary: New developments and upgrades in synchrotron facilities have allowed for better study of complex structures with improved resolution. However, the larger amount of data collected poses challenges for manual processing. This study proposes a deep convolutional neural network model that uses machine learning to automatically segment precipitates and porosities in synchrotron transmission X-ray micrograms. Experimental results show that the model can efficiently process large data sets and has potential for various applications.
JOURNAL OF SYNCHROTRON RADIATION
(2022)
Article
Materials Science, Multidisciplinary
Stavros Samothrakitis, Camilla Buhl Larsen, Jan Capek, Efthymios Polatidis, Marc Raventos, Michael Tovar, Soren Schmidt, Markus Strobl
Summary: For polycrystalline materials, crystallographic orientation plays a crucial role in determining key material properties. Laue three-dimensional neutron diffraction has shown promising results in indexing grain orientations in centimeter-sized samples with statistical significance, providing a novel non-destructive method for crystallographic characterization.
MATERIALS TODAY ADVANCES
(2022)
Article
Materials Science, Multidisciplinary
J. Capek, E. Polatidis, N. Casati, R. Pederson, C. Lyphout, M. Strobl
Summary: A comprehensive investigation was conducted on the effect of laser scanning pattern on the microstructure of cylindrical samples made of Alloy 718 processed by Laser Powder Bed Fusion. The study found that the common alternate direction scanning resulted in a more homogeneous microstructure, while the less common concentric line scans led to significant microstructural heterogeneities between the edges and the center of the sample. The investigation emphasized the importance of processing parameters on microstructure homogeneity and the effect of chemical variations on the determination of residual stresses, particularly in materials like Alloy 718 with strong local chemical variations due to different types and extent of precipitation.
MATERIALS & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Tiago A. Rodrigues, Francisco Werley Cipriano Farias, Kaiping Zhang, A. Shamsolhodaei, Jiajia Shen, N. Zhou, Norbert Schell, Jan Capek, E. Polatidis, Telmo G. Santos, J. P. Oliveira
Summary: In this study, a functionally graded material (FGM) of 316L stainless steel to Inconel 625 was built using Twin-Wire and Arc Additive Manufacturing (T-WAAM) with different deposition strategies. The properties of the FGM were found to be superior with a direct interface, showing higher strengths and elongations upon failure, as well as lower residual stresses.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Chemistry, Multidisciplinary
Florencia Malamud, Javier Roberto Santisteban, Miguel Angel Vicente Alvarez, Matteo Busi, Efthymios Polatidis, Markus Strobl
Summary: This paper presents a model for describing the attenuation coefficient of textured polycrystalline materials based on a single-crystal to polycrystalline approach. The model evaluates the Bragg contribution to the attenuation coefficient as a combination of the Bragg-reflected component of imperfect single crystals with different orientations. The model's optimization is demonstrated through experiments on calibration samples and its ability to simulate textured samples in different orientations.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2023)
Article
Materials Science, Multidisciplinary
Shieren Sumarli, Efthymios Polatidis, Florencia Malamud, Matteo Busi, Claire Navarre, Reza Esmaeilzadeh, Roland Loge, Markus Strobl
Summary: Spatially resolved studies of crystalline structures, such as lattice spacings, can be conducted using neutron Bragg edge imaging. However, extracting strain distribution becomes challenging when the strain varies across the thickness of the probed specimen. This study introduces an approach to separate the transmission spectra of two different material states, which is particularly useful for operando strain characterization in powder bed additive manufacturing environments.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Manufacturing
Konstantinos A. Liogas, Kwang Boon Lau, Zifan Wang, David N. Brown, Efthymios Polatidis, Pei Wang, Alexander M. Korsunsky
Summary: Equiatomic Co-Fe alloy with controlled slow cooling through thermal post-processing has shown excellent soft magnetic properties, making it suitable for manufacturing three-dimensional complex-shaped electromagnetic cores using Laser Powder Bed Fusion technique.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Manufacturing
S. Gaudez, M. Ben Haj Slama, E. Heripre, L. Yedra, M. Scheel, S. Hallais, M. V. Upadhyay
Summary: During additive manufacturing of stainless steels, sub-micron sized oxide and non-oxide precipitates form, and a recent study confirmed that the precipitate composition can evolve during subsequent solid-state thermal cycling (SSTC). However, the study couldn't provide evidence on precipitate volume fraction, density, and size evolution. In this work, a novel experimental procedure was used to quantify these changes, revealing that new oxides nucleated during rapid SSTC, but dissolve during slow SSTC and annealing due to oxygen evaporation.
ADDITIVE MANUFACTURING
(2023)
Article
Materials Science, Multidisciplinary
Y. Liu, K. Zweiacker, C. Liu, J. T. McKeown, J. M. K. Wiezorek
Summary: The evolution of rapid solidification microstructure and solidification interface velocity of hypereutectic Al-20at.%Cu alloy after laser melting has been studied experimentally. It was found that the formation of microstructure was dominated by eutectic, alpha-cell, and banded morphology grains, and the growth modes changed with increasing interface velocity.
Article
Materials Science, Multidisciplinary
Bharat Gwalani, Julian Escobar, Miao Song, Jonova Thomas, Joshua Silverstein, Andrew Chihpin Chuang, Dileep Singh, Michael P. Brady, Yukinori Yamamoto, Thomas R. Watkins, Arun Devaraj
Summary: Castable alumina forming austenitic alloys exhibit superior creep life and oxidation resistance at high temperatures. This study reveals the mechanism behind the enhanced creep performance of these alloys by suppressing primary carbide formation and offers a promising alloy design strategy for high-temperature applications.
Article
Materials Science, Multidisciplinary
Jian Song, Qi Zhang, Songsong Yao, Kunming Yang, Houyu Ma, Jiamiao Ni, Boan Zhong, Yue Liu, Jian Wang, Tongxiang Fan
Summary: Recent studies have shown that achieving an atomically flat surface for metals can greatly improve their oxidation resistance and enhance their electronic-optical applications. Researchers have explored the use of graphene as a covering layer to achieve atomically flat surfaces. They found that high-temperature deposited graphene on copper surfaces formed mono-atomic steps, while annealed copper and transferred graphene on copper interfaces formed multi-atomic steps.
Article
Materials Science, Multidisciplinary
Jennifer A. Glerum, Jon-Erik Mogonye, David C. Dunand
Summary: Elemental powders of Al, Ti, Sc, and Zr are blended and processed via laser powder-bed fusion to create binary and ternary alloys. The microstructural analysis and mechanical testing show that the addition of Ti results in the formation of primary precipitates, while the addition of Sc and Zr leads to the formation of fine grain bands. The Al-0.25Ti-0.25Zr alloy exhibits comparable strain rates to Al-0.5Zr at low stresses, but significantly higher strain rates at higher stresses during compressive creep testing. Finite element modeling suggests that the connectivity of coarse and fine grain regions is a critical factor affecting the creep resistance of the alloys.
Article
Materials Science, Multidisciplinary
P. Jannotti, B. C. Hornbuckle, J. T. Lloyd, N. Lorenzo, M. Aniska, T. L. Luckenbaugh, A. J. Roberts, A. Giri, K. A. Darling
Summary: This work characterizes the thermo-mechanical behavior of bulk nanocrystalline Cu-Ta alloys under extreme conditions. The experiments reveal that the alloys exhibit unique mechanical properties, behaving differently from conventional nanocrystalline Cu. They do not undergo grain coarsening during extrusion and exhibit behavior similar to coarse-grained Cu.
Article
Materials Science, Multidisciplinary
Yiqing Wei, Jingwei Li, Daliang Zhang, Bin Zhang, Zizhen Zhou, Guang Han, Guoyu Wang, Carmelo Prestipino, Pierric Lemoine, Emmanuel Guilmeau, Xu Lu, Xiaoyuan Zhou
Summary: This study proposes a new strategy to modify microstructure by phase regulation, which can simultaneously enhance carrier mobility and reduce lattice thermal conductivity. The addition of Cu in layered SnSe2 induces a phase transition that leads to increased grain size and reduced stacking fault density, resulting in improved carrier mobility and lower lattice thermal conductivity.
Article
Materials Science, Multidisciplinary
Jia Chen, Zhengyu Zhang, Eitan Hershkovitz, Jonathan Poplawsky, Raja Shekar Bhupal Dandu, Chang-Yu Hung, Wenbo Wang, Yi Yao, Lin Li, Hongliang Xin, Honggyu Kim, Wenjun Cai
Summary: In this study, the structural origin of the pH-dependent repassivation mechanisms in multi-principal element alloys (MPEA) was investigated using surface characterization and computational simulations. It was found that selective oxidation in acidic to neutral solutions leads to enhanced nickel enrichment on the surface, resulting in reduced repassivation capability and corrosion resistance.
Article
Materials Science, Multidisciplinary
X. Y. Xu, C. P. Huang, H. Y. Wang, Y. Z. Li, M. X. Huang
Summary: The limited slip systems of magnesium (Mg) and its alloys hinder their wide applications. By conducting tensile straining experiments, researchers discovered a rate-dependent transition in the dislocation mechanisms of Mg alloys. At high strain rates, glissile dislocations dominate, while easy-glide dislocations dominate at low strain rates. Abundant glissile dislocations do not necessarily improve ductility.
Article
Materials Science, Multidisciplinary
M. S. Szczerba, M. J. Szczerba
Summary: Inverse temperature dependences of the detwinning stress were observed in face-centered cubic deformation twins in Cu-8at.%Al alloy. The detwinning stress increased with temperature when the pi detwinning mode was involved, but decreased when the pi/3 mode was involved. The dual effect of temperature on the detwinning stress was due to the reduction of internal stresses pre-existing within the deformation twins. The complete reduction of internal stresses at about 530 degrees C led to the equivalence of the critical stresses of different detwinning modes and a decrease in the yield stress anisotropy of the twin/matrix structure.
Article
Materials Science, Multidisciplinary
Taowen Dong, Tingting Qin, Wei Zhang, Yaowen Zhang, Zhuoran Feng, Yuxiang Gao, Zhongyu Pan, Zixiang Xia, Yan Wang, Chunming Yang, Peng Wang, Weitao Zheng
Summary: The interaction between the electrode and the electric double layer (EDL) significantly influences the energy storage mechanism. By studying the popular alpha-Fe2O3 electrode and the EDL interaction, we find that the energy storage mechanism of the electrode can be controlled by modulating the EDL.
Article
Materials Science, Multidisciplinary
Matthew R. Barnett, Jun Wang, Sitarama R. Kada, Alban de Vaucorbeil, Andrew Stevenson, Marc Fivel, Peter A. Lynch
Summary: The elastic-plastic transition in magnesium alloy Mg-4.5Zn exhibits bursts of deformation, which are characterized by sudden changes in grain orientation. These bursts occur in a coordinated manner among nearby grains, with the highest burst rate observed at the onset of full plasticity. The most significant burst events are associated with twinning, supported by the observation of twinned structures using electron microscopy. The bursts are often preceded and followed by a stasis in peak movement, indicating a certain "birth size" for twins upon formation and subsequent growth at a later stage.
Article
Materials Science, Multidisciplinary
Vaidehi Menon, Sambit Das, Vikram Gavini, Liang Qi
Summary: Understanding solute segregation thermodynamics is crucial for investigating grain boundary properties. The spectral approach and thermodynamic integration methods can be used to predict solute segregation behavior at grain boundaries and compare with experimental observations, thus aiding in alloy design and performance control.
Article
Materials Science, Multidisciplinary
Feiyu Qin, Lei Hu, Yingcai Zhu, Yuki Sakai, Shogo Kawaguchi, Akihiko Machida, Tetsu Watanuki, Yue-Wen Fang, Jun Sun, Xiangdong Ding, Masaki Azuma
Summary: This study reports on the negative and zero thermal expansion properties of Cd2Re2O7 and Cd1.95Ni0.05Re2O7 materials, along with their ultra-low thermal conductivity. Through investigations of their structures and phonon calculations, the synergistic effect of local structure distortion and soft phonons is revealed as the key to achieving these distinctive properties.
Article
Materials Science, Multidisciplinary
Thomas Beerli, Christian C. Roth, Dirk Mohr
Summary: A novel testing system for miniature specimens is designed to characterize the plastic response of materials for which conventional full-size specimens cannot be extracted. The system has an automated operation process, which reduces the damage to specimens caused by manual handling and improves the stability of the test results. The experiments show that the miniature specimens extracted from stainless steel and aluminum have high reproducibility, and the results are consistent with those of conventional-sized specimens. A correction procedure is provided to consider the influence of surface roughness and heat-affected zone caused by wire EDM.
Article
Materials Science, Multidisciplinary
Rani Mary Joy, Paulius Pobedinskas, Nina Baule, Shengyuan Bai, Daen Jannis, Nicolas Gauquelin, Marie-Amandine Pinault-Thaury, Francois Jomard, Kamatchi Jothiramalingam Sankaran, Rozita Rouzbahani, Fernando Lloret, Derese Desta, Jan D'Haen, Johan Verbeeck, Michael Frank Becker, Ken Haenen
Summary: This study investigates the influence of film microstructure and composition on the Young's modulus and residual stress in nanocrystalline diamond thin films. The results provide insights into the mechanical properties and intrinsic stress sources of these films, and demonstrate the potential for producing high-quality nanocrystalline diamond films under certain conditions.