-
Orientation distribution and deviation behaviors of dislocation loops in a quenched Al-Cu alloy Acta Mater. (IF 9.4) Pub Date : 2024-03-18 Rui Fu, Zongqiang Feng, Xiaoxu Huang
Dislocation loops in quenched aluminum alloys are usually seen deviating from their nominal habit planes, while the orientation distribution and deviation mechanism are far from understanding. Based on the method of tomographic crystallography of dislocations and correlative heating experiments in transmission electron microscopy (TEM), we revisit the three-dimensional (3D) characteristics and deviation
-
Electronic structure along Sm[formula omitted]Co[formula omitted]Ge[formula omitted] twin boundaries Acta Mater. (IF 9.4) Pub Date : 2024-03-18 Ellis Kennedy, Trent M. Kyrk, Colin Ophus, Gregory T. McCandless, Julia Y. Chan, M.C. Scott
LnCoGe (Ln = lanthanide) intermetallics possess intriguing electronic and magnetic properties. The compound SmCoGe exhibits antiferromagnetic ordering coupled with a magnetic moment of that exceeds the theoretical moment of trivalent Sm suggesting a magnetic contribution from Co. Twinning is observed in Sn flux-grown monoclinic SmCoGe along (100) planes. While the influence of twin boundaries on superconducting
-
Crystal plasticity simulations reveal cooperative plasticity mechanisms leading to enhanced strength and toughness in gradient nanostructured metals Acta Mater. (IF 9.4) Pub Date : 2024-03-16 Claire Griesbach, Curt A. Bronkhorst, Ramathasan Thevamaran
Heterogeneous deformation is thought to provide the strengthening in gradient nanostructured metals, but the underlying plasticity mechanisms and optimal gradient structures for attaining improved mechanical performance remain elusive. Through crystal plasticity simulations of three-dimensional heterogeneous nanostructures, we reveal the heterogeneous-deformation-induced plasticity mechanisms which
-
Insights into Primary Carbides and Nanoparticles in an Additively Manufactured High-alloy Steel Acta Mater. (IF 9.4) Pub Date : 2024-03-16 Huayue Zhang, Hui Peng, Paul A.J. Bagot, Yiqiang Wang, Diego Alba Venero, Stuart Robertson, Gebril M.A.M. El-Fallah, Hongbo Guo, Michael P. Moody, Bo Chen
This paper reports the use of combined electron microscopy and small-angle neutron scattering (SANS) to probe into the compositional and size evolution of the primary carbides and nanoparticles (defined by a size threshold of 100 nm) in an additively manufactured high-alloy steel before and after heat treatment. The primary carbides exhibit marginal changes in their total volume fraction and size after
-
Morphology, mechanical properties, and oxidation behavior of stoichiometric Ti0.33-xAlxB0.67 coatings (x = 0.04, 0.15, 0.21, and 0.28) Acta Mater. (IF 9.4) Pub Date : 2024-03-16 Amir Hossein Navidi Kashani, Marcus Hans, Sebastian Lellig, Damian M. Holzapfel, Lukas Löfler, Stanislav Mráz, Daniel Primetzhofer, Johann Michler, Jochen M. Schneider
[Display omitted]
-
Effect of non-clustering element C and Mo on irradiation-induced clustering in reactor pressure vessel steels Acta Mater. (IF 9.4) Pub Date : 2024-03-14 Yang Kong, Jing Xue, Shenbao Jin, Hongmei Zhu, Gang Sha
Commercial reactor pressure vessel steels in nuclear power plant applications contain C and other minor non-clustering elements in addition to the clustering elements of Mn, Ni and Si. However, the effect of such non-clustering elements on irradiation-induced solute clustering in ferritic steels has seldom been addressed. Herein, we reveal that a commercial RPV steel and its Fe-Mn-Ni-Si model alloy
-
Peculiar martensitic microstructure and dislocation accumulation behavior in Ti-Ni-Cu shape memory alloys almost satisfying the triplet condition Acta Mater. (IF 9.4) Pub Date : 2024-03-13 A. Heima, Y. Shinohara, H. Akamine, M. Nishida, T. Inamura
Dislocation accumulation behavior at the lattice correspondence variant (CV) triplets of the Ti-Ni-Cu alloy close to the triplet condition (TC) was investigated by using in situ heating transmission electron microscopy observation. The martensitic microstructure of this alloy was peculiar because of no {011} compound twin laminate as predicted by the phenomenological theory of martensite crystallography
-
Corrigendum to ‘Phase transformation induced transitional twin boundary in body-centered cubic metals’[Acta Materialia 249 (2023) 118815] Acta Mater. (IF 9.4) Pub Date : 2024-03-13 Xiyao Li, Qingkun Zhao, Yanzhong Tian, Qiannan Wang, Jitang Fan, Kexing Song, Haofei Zhou, Jiangwei Wang
-
Atomic-scale understanding of twin intersection rotation and ε-martensite transformation in a high Mn twinning-induced plasticity steel Acta Mater. (IF 9.4) Pub Date : 2024-03-12 Jun Chen, Song Lu, Zi-yong Hou, Wen-wen Song, Zhen-yu Liu, Guo-dong Wang, Tadashi Furuhara
Twin intersections have been reported to significantly impact on macroscopic properties by relaxing localized stress concentration and accommodating strain. Here the atomic-scale structural characterization of the twin intersection region in a deformed high Mn twinning-induced plasticity (TWIP) steel was conducted using high-resolution transmission electron microscopy. Detailed microstructural features
-
Grain growth competition and formation of grain boundaries during solidification of hcp alloys Acta Mater. (IF 9.4) Pub Date : 2024-03-12 A.K. Boukellal, M. Sarebanzadeh, A. Orozco-Caballero, F. Sket, J. LLorca, D. Tourret
Grain growth competition during directional solidification of a polycrystal with hexagonal (hcp) symmetry (Mg-1wtGd alloy) is studied by phase-field modeling, exploring the effect of the temperature gradient on the resulting grain boundary (GB) orientation selection. Results show that selection mechanisms and scaling laws derived for cubic (fcc, bcc) crystals also apply to hcp materials (within their
-
On the habit planes between elastically distorted austenite and martensite in NiTi Acta Mater. (IF 9.4) Pub Date : 2024-03-09 Luděk Heller, Petr Šittner
The cubic B2 to monoclinic B19’ martensitic transformation in NiTi shape memory alloys proceeds by the nucleation and propagation of habit plane interfaces that remain undistorted and unrotated during the transformation. Due to incompatibility of austenite and martensite lattices in NiTi, habit plane interfaces are assumed to form between austenite and twinned martensite as described by Phenomenological
-
Recoverable tuning of lattice mismatch and strength in ultrastable-nanostructured Cu/Ag spinodoid alloys Acta Mater. (IF 9.4) Pub Date : 2024-03-09 Sheng-Nan Yang, Hui Xie, Huai Guan, Hai-Jun Jin
The strengthening effect of interface in materials is usually studied by monitoring the change of strength in response to varying structure sizes, such as the varying grain or phase sizes. In this study, we demonstrate that the strength of a nanostructured material can be recoverably tuned by modifying interfacial structure without changing structure size. Specifically, we studied the Cu/Ag spinodoid
-
In situ study and assessment of the phosphorus-induced solute drag effect on the grain boundary mobility of austenite Acta Mater. (IF 9.4) Pub Date : 2024-03-09 Maximilian Kern, Michael Bernhard, Youn-Bae Kang, Christian Bernhard
The solute drag effect of phosphorus (P) in the single-phase austenite (γ-Fe) region was studied under isothermal annealing conditions at temperatures of 1050 °C, 1150 °C, 1250 °C and 1350 °C. High-temperature laser scanning confocal microscopy (HT-LSCM) was used to observe and quantify grain growth on the surface of three different samples containing 0.026 wt.-% P, 0.044 wt.-% P and 0.102 wt.-% P
-
He bubble-induced phase transformation of W grain boundaries revealed by accelerated molecular dynamics Acta Mater. (IF 9.4) Pub Date : 2024-03-09 Peter Hatton, Danny Perez, Timofey Frolov, Blas Pedro Uberuaga
The growth of He bubbles and the resulting impact on the microstructural evolution of W are of paramount importance to the plasma-facing materials community due to the application of W in Tokamak fusion reactors. Using accelerated molecular dynamics (AMD) techniques, we outline the structural evolution of grain boundaries (GBs) caused by growing He bubbles. It is discovered that when an alternative
-
A process-structure-property model via physics-based/data-driven hybrid methods for freeze-cast porous ceramics in Si3N4-Si2N2O case system Acta Mater. (IF 9.4) Pub Date : 2024-03-09 Xingqi Liao, Mingqing Liao, Chong Wei, Zhiheng Huang, Wenjiu Duan, Xiaoming Duan, Delong Cai, Laurent Gremillard, Zhihua Yang, Dechang Jia, Yu Zhou
For the engineering applications of freeze-cast porous ceramics, the demand targets are often multiple and competing, which is a challenging problem to seek a Nash equilibrium in the high-dimensional design space. An accurate and robust quantification of process-structure-property correlations would provide an effective path to find the set of Pareto optimal materials for one specific need. In this
-
Achieving strength-ductility synergy in zirconium via ultra-dense twin-twin networks Acta Mater. (IF 9.4) Pub Date : 2024-03-09 Xi-Heng Lin, Wei-Zhong Han
Hierarchical nano-twinned structures have been proven to be an effective way in breaking the strength-ductility dilemma in face-centered cubic metals. However, it is challenging to introduce high-density of twinned structures in hexagonal-close packed (HCP) metals because deformation twinning are limited in fine-grained structures. Here, we propose an approach to introduce ultra-dense twin-twin networks
-
Atomic structure of clusters and GP-zones in an Al-Mg-Si alloy Acta Mater. (IF 9.4) Pub Date : 2024-03-08 Calin D. Marioara, Sigmund J. Andersen, Christoph Hell, Jonas Frafjord, Jesper Friis, Ruben Bjørge, Inga G. Ringdalen, Olaf Engler, Randi Holmestad
The structures of atomic clusters and GP-zones preceding precipitation in an Al-0.70Mg-0.85Si-0.15Fe-0.25Mn (wt. %) alloy have been investigated by annular dark field scanning transmission electron microscopy imaging and density functional theory calculations. One analysed condition consisted of one-month natural aging, and another was in a pre-baked state after 24 h aging at 90 °C. To quantify the
-
Deformation mechanisms and their role in the lack of ductility in the refractory-based high entropy alloy AlMo0.5NbTa0.5TiZr Acta Mater. (IF 9.4) Pub Date : 2024-03-07 Gopal B. Viswanathan, Zachary T. Kloenne, Jean-Philippe Couzinié, Brian A. Welk, Samuel J. Kuhr, Hamish L. Fraser
The deformation mechanisms in the refractory high entropy alloy AlMoNbTaTiZr have been investigated, with their potential impact on ductility. Specifically, the modes of plasticity active in the B2 matrix and in an alloyed version of the phase AlZr found at grain and subgrain boundaries were explored by use of nano-indentation. For the B2 phase, a combination of weak-beam dark-field and superlattice
-
A simpler technique for determining substitutional solute-screw dislocation interaction energies in BCC structures useful for estimating solid solution screw strengthening Acta Mater. (IF 9.4) Pub Date : 2024-03-05 S.I. Rao, B. Akdim
A new simpler method of calculating solute-screw dislocation interaction energies in BCC structures using a combination of row potential formalism and non-linear elasticity dilatational field at the core of screw dislocations is presented. Such a technique is used with simple interatomic potentials as well as first principles calculations and applied to solutes in pure Nb, NbTaTi and NbTiZr. The row
-
Extracting free energies from local composition fluctuations in solids: A frequency distribution analysis of simulated atom probe data obtained by TAPSim Acta Mater. (IF 9.4) Pub Date : 2024-03-04 Jianshu Zheng, Marvin Poul, Guido Schmitz, Sebastian M. Eich
The present work proposes a novel methodology to extract direct thermodynamic information, i.e. Gibbs free energies, from local composition fluctuations found in atom probe data based on statistical mechanics. The proof-of-concept is demonstrated with an exemplary simulated Cu–Ni alloy, which has first been equilibrated using Monte Carlo techniques with an embedded-atom method potential and subsequently
-
Effect of cluster chemistry on the strengthening of Al alloys Acta Mater. (IF 9.4) Pub Date : 2024-03-04 Yixin Wang, Xinren Chen, Huan Zhao, Wenwen Sun, Qi Zhang, Baptiste Gault, Christopher Hutchinson
When a supersaturated Al solid solution is held at room temperature, natural ageing occurs through the formation of clusters/zones providing a strengthening of the material. Recently, it was shown that this process can be greatly amplified by applying a cyclic plastic strain to a supersatured Al alloy. The cyclic strengthening also leads to a microstructure dominated by clusters/zones but the strengths
-
Heterogeneous precipitate microstructure design in β-Ti alloys by regulating the cooling rate Acta Mater. (IF 9.4) Pub Date : 2024-03-02 Mengyuan Hao, Dong Wang, Yalong Wang, Tianlong Zhang, Pei Li, Yaning Guo, Yufeng Zheng, Qiaoyan Sun, Yunzhi Wang
Cooling after solutionizing or aging plays a crucial role in heat treatment and can greatly influence the final precipitate microstructure and mechanical properties of titanium (Ti) alloys. In this study, we employ phase field simulations to strategically engineer heterogeneous precipitate microstructures in near β-Ti alloys by manipulating the cooling rate, which leads to different phase transition
-
Mechanisms of structural evolution of laminates with immiscible components under high-pressure torsion Acta Mater. (IF 9.4) Pub Date : 2024-03-01 A. Mazilkin, V. Tavakkoli, O. Davydenko, Y. Beygelzimer, E. Boltynjuk, T. Boll, B. Straumal, B. Baretzky, Y. Estrin, R. Kulagin
The mechanism of structural evolution of a three-layer Cu-Mo-Cu laminate under high-pressure torsion (HPT) was studied using scanning and transmission electron microscopy, atom probe tomography, and nanoindentation, complemented with finite element calculations. The results demonstrate a gradual refinement of the structure of the Mo component; a greater degree of refinement is observed in the peripheral
-
Sub-stoichiometry and vacancy structures in V/Nb carbide precipitates by cluster expansion and first-principles calculations Acta Mater. (IF 9.4) Pub Date : 2024-03-01 Xiaohan Bie, Jie Hou, Xiao Zhou, Jun Song
Carbide precipitates, particularly V/Nb carbides, play a vital role in modulating many properties, including strength, hardness, wear resistance and hydrogen embrittlement (HE) susceptibility of steels. Our work presented a comprehensive study employing a cluster expansion (CE) approach combined with first-principles calculations to investigate the sub-stoichiometry induced by C vacancies within V/Nb
-
Kinetic Monte Carlo simulations of solute clustering during quenching and aging of Al–Mg–Zn alloys Acta Mater. (IF 9.4) Pub Date : 2024-03-01 Zhucong Xi, Louis G. Hector Jr., Amit Misra, Liang Qi
The physical mechanisms behind cluster formation during quenching and aging of age-hardening metallic alloys are poorly understood based on classical nucleation and growth theories, especially in multicomponent alloys with supersaturated vacancies and fast-diffusing solute atoms. Here, solute clustering in an Al–Mg–Zn alloy during quenching immediately after high-temperature (800 K) solution treatment
-
Harnessing intrinsic defect complexes for visible-light-driven photocatalytic activity in Delafossite CuAlO2 Acta Mater. (IF 9.4) Pub Date : 2024-02-29 Jia-Xin Zhang, Zong-Yan Zhao, Tian-Long Yang, Jian Yang, Jin Zhang, Qing-Ju Liu, Yongbo Kuang
This study significantly enhances the photo(electro)catalytic capabilities of CuAlO, a wide bandgap semiconductor, through targeted defect engineering. By employing a tailored solid-state reaction under a mixed oxygen-argon atmosphere, an intrinsic defect complex of [O+Cu] into has been successfully integrated into CuAlO, thereby expanding its light absorption to the visible spectrum. The optimized
-
Quantitatively evaluating the contribution of intergranular carbides, Cr-depleted zone, and grain boundary to intergranular stress corrosion cracking of Alloy 600 in a simulated boiling water reactors environment with high oxygen concentrations Acta Mater. (IF 9.4) Pub Date : 2024-02-29 Pan Liu, Yunlong Wu, Xiangyu Zhong, Zihao Wang, Ken Oyama, Seiya Ogota, Yutaka Watanabe, Tetsuo Shoji
In this work, the microstructure and stress corrosion cracking (SCC) behavior of Alloy 600 exposed to various sensitization parameters and subsequent cold work under simulated boiling water reactor (BWR) condition with high oxygen concentrations were systematically studied to meet the new situation. Larger and more dispersed intergranular (IG) carbides, and wider Cr-depleted zones (CrDZ) with less
-
Evolution of texture and intergranular stresses of αZr and minority phases in Zr-2.5Nb pressure tube through synchrotron X-ray diffraction Acta Mater. (IF 9.4) Pub Date : 2024-02-29 M.A. Vicente Alvarez, Constanza Buioli, J. Santisteban, P. Vizcaino
This study investigates the impact of different processing steps on the crystallographic texture evolution of αZr and minority phases βZr and ωZr, and intergranular stresses as a function of grain orientation in a Zr2.5Nb pressure tube. This was done by analysis of diffraction data recorded in the 1-ID line of the Advanced Photon Source for high energy X-Rays (∼80Kev) in transmission geometry on three
-
Grain boundary diffusion in a compositionally complex alloy: Interplay of segregation, precipitation and interface structures in a Ni–Cr–Mo alloy Acta Mater. (IF 9.4) Pub Date : 2024-02-29 Baixue Bian, Lana Söltzer, G. Mohan Muralikrishna, Shabnam Taheriniya, Sandipan Sen, K.C. Hari Kumar, Sankaran S., Gerhard Wilde, Sergiy V. Divinski
Grain boundary complexions in the Hastelloy C-22 are modified to unravel the structure–property interplay of grain boundary precipitation (carbides), segregation, and grain boundary diffusion rates. Annealing treatments are used to create distinct grain boundary complexions with specific segregation-precipitation-structure states. Two grain boundary states were compared: those induced by low- (at 873
-
Efficiency, accuracy, and transferability of machine learning potentials: Application to dislocations and cracks in iron Acta Mater. (IF 9.4) Pub Date : 2024-02-29 Lei Zhang, Gábor Csányi, Erik van der Giessen, Francesco Maresca
Machine learning interatomic potentials (ML-IAPs) enable quantum-accurate, classical molecular dynamics simulations of large systems, beyond reach of density functional theory (DFT). Yet, their efficiency and ability to predict systems larger than DFT supercells are not fully explored, posing a question regarding transferability to large-scale simulations with defects (e.g. dislocations, cracks). Here
-
The Effect of Grain Boundary Facet Junctions on Segregation and Embrittlement Acta Mater. (IF 9.4) Pub Date : 2024-02-29 M.E. Fernandez, R. Dingreville, D.L. Medlin, D.E. Spearot
Junctions are discontinuities in flat grain boundaries that arise in all polycrystalline materials and are thought to play important roles in the response of a grain boundary network to thermal and mechanical loads. A key open question concerns the mechanisms by which solute segregation to junctions impacts properties of the grain boundary. In this work, we investigate the influence of grain boundary
-
Theory-guided materials design of multiphase alloys with superior stiffness at finite temperatures Acta Mater. (IF 9.4) Pub Date : 2024-02-28 Jinhui Huang, Shuhong Liu, Martin Friák, Chengliang Qiu, Shun-Li Shang, Zi-Kui Liu, Yong Du
Aiming at designing Mg alloys with a significantly increased stiffness at elevated temperatures, we propose a high-precision multi-scale methodology to compute temperature-dependent elastic modulus of homogeneous multiphase alloys. The proposed method combines (i) first-principles calculations of temperature- and solid solubility-dependent elastic properties in individual phases with (ii) a two-level
-
Metastable phase separation and crystalline orientation feature of electromagnetic levitation processed CoCrCuFeNi high entropy alloy Acta Mater. (IF 9.4) Pub Date : 2024-02-28 P.X. Yan, J. Chang, W.L. Wang, X.N. Zhu, M.J. Lin, B. Wei
The metastable liquid phase separation and rapid solidification kinetics of CoCrCuFeNi high entropy alloy (HEA) has been investigated by electromagnetic levitation (EML) technique. The maximum liquid undercooling attained 452 K (0.27), and the critical undercooling to initiate phase separation was determined as 172 K. By modulating the degree of alloy undercooling, the overall macrosegragation pattern
-
Evaluation of hydrogen interactions with defects induced by deformation in the duplex stainless steel microstructure: An internal friction study Acta Mater. (IF 9.4) Pub Date : 2024-02-27 Liese Vandewalle, Lisa Claeys, Milan J. Konstantinović, Kim Verbeken, Tom Depover
Despite their good corrosion resistance and optimal mechanical properties, duplex stainless steels are affected by hydrogen embrittlement. Therefore, understanding the hydrogen-defect interactions in these steels is crucial. This study uses internal friction to evaluate the interactions of hydrogen with microstructural defects. Analysis of the internal friction spectra of the steels subjected to straining
-
A spatially resolved analysis of dislocation loop and nanohardness evolution in proton irradiated Zircaloys Acta Mater. (IF 9.4) Pub Date : 2024-02-27 Ö. Koç, R. Thomas, X.Z. Liang, Z. Hegedüs, U. Lienert, R.W. Harrison, M. Preuss, T. Ungár, P. Frankel
Proton irradiation is increasingly used as a surrogate for neutron irradiation, providing similar damage structures at significantly lower costs and less time compared to neutron irradiation. However, in contrast to neutrons, protons produce a depth dependent damage profile that incorporates a plateau region and a Bragg peak in the tens of microns region depending on the material and proton energy
-
Deciphering the Mixed-Alkali effect in supercooled oxide liquids: Results from dynamic and thermodynamic measurements Acta Mater. (IF 9.4) Pub Date : 2024-02-27 Tae-min Yeo, Jung-Wook Cho, Sabyasachi Sen
The fundamental nature of the mixed-alkali effect (MAE) on viscosity, fragility index and glass transition of supercooled borate and phosphate liquids is studied using a combination of dynamic and thermodynamic measurements. The negative deviation of from linearity in mixed-alkali borates is found to be always the largest when two distinct alkalis are combined in equal proportions, consistent with
-
Corrigendum to “Efficient searching of processing parameter space to enable inverse microstructural design of materials” [Acta Materialia 264 (2024) 119562] Acta Mater. (IF 9.4) Pub Date : 2024-02-26 Dung-Yi Wu, Todd C. Hufnagel
-
High-pressure phase transitions in a laser directed energy deposited Fe-33Cu Alloy Acta Mater. (IF 9.4) Pub Date : 2024-02-26 Daniel Yin, Bibhu Prasad Sahu, Phillip Tsurkan, Dmitry Popov, Avinash M. Dongare, Nenad Velisavljevic, Amit Misra
Additively manufactured Fe-Cu alloys contain both equilibrium face-centered cubic (FCC) and metastable body-centered cubic (BCC) crystal structure Cu precipitates depending on their size. However, the stability of these nanoscale precipitates under extreme conditions such as high pressures has not been reported. This study investigates the phase transformations and microstructural stability of laser
-
Thermal diffusion and microstructural evolution of Cu-Zn binary system under hypergravity Acta Mater. (IF 9.4) Pub Date : 2024-02-26 Lilin Xie, Yisheng Zheng, Hui Lu, Yilin Jiao, Yao Qu, Jixiang Cai, Yadi Zhai, Yanhui Chen, Shengcheng Mao, Xiaodong Han
It has long been a common assumption that the stress conditions for materials operating in hypergravity could be simplified to traditional stress conditions. However, such simplification has not been experimentally verified. In this study, we examined the thermal diffusion and microstructural evolution of the Cu-Zn binary system under hypergravity levels of up to 4700 (: gravity of Earth, 9.8 m/s)
-
Microstructure evolution and strengthening mechanism of FeCo-1.5V0.5Nb0.4 W soft magnetic alloy rolled strip with high yield strength and low coercivity Acta Mater. (IF 9.4) Pub Date : 2024-02-24 Mingyuan Ma, Xuan Zhao, Xueyin Sun, Jiantang Jiang, Wenzhu Shao, Liang Zhen
The low strength of soft magnetic alloy limits the ability to operate high speed rotors in aero-generators. Strengthening of soft magnetic alloys remains a challenge, as most methods that enhance strength lead to the deterioration of magnetic properties. In this work, a rolled strip of FeCo-1.5V0.5Nb0.4W (wt.%) alloy with high yield strength and low coercivity was developed. We demonstrated that minor
-
In situ epitaxial thickening of wafer-scale, highly oriented nanotwinned Ag on tailored polycrystalline Cu substrates Acta Mater. (IF 9.4) Pub Date : 2024-02-24 Xiaofei Zhan, Zengwei Zhu
Highly (111)-oriented nanotwinned Ag (nt-Ag) is a promising candidate for a next-generation direct metal bonding material without a vacuum environment. However, conventional methods used for its preparation are costly, complex, and inefficient. Herein, we report an epitaxial thickening approach of wafer-scale (111) nt-Ag on tailored polycrystalline Cu substrates via a galvanic replacement reaction
-
Influence of microstructure heterogeneity on the tensile response of an Aluminium alloy designed for laser powder bed fusion Acta Mater. (IF 9.4) Pub Date : 2024-02-23 Maxence Buttard, Béchir Chéhab, Charles Josserond, Frédéric Charlot, Pierre Lhuissier, Xavier Bataillon, Alexis Deschamps, Julie Villanova, Marc Fivel, Jean-Jacques Blandin, Guilhem Martin
Aluminium alloys designed for additive manufacturing with Zr addition exhibit heterogeneous microstructures from the grain scale down to the atomic scale. Bimodal grain structures with submicron equiaxed grains near the melt pool boundaries and columnar grains at the melt pool interiors are observed. The regions consisting of submicron grains are interconnected in 3D. The tensile response of these
-
Carbon solute drag effect on the growth of carbon supersaturated bainitic ferrite: Modeling and experimental validations Acta Mater. (IF 9.4) Pub Date : 2024-02-23 Zongbiao Dai, Hao Chen, Junjie Sun, Sybrand van der Zwaag, Jun Sun
The carbon partitioning and lengthening rate of bainitic ferrite () are excellent experimental parameters to estimate our level of understanding of the mechanism of bainitic transformation from a continuum perspective and our ability to capture it in analytical expressions. For Fe-C alloys and relatively simple steels the classical Zener-Hillert theory captures the bainitic transformation rather well
-
Variation of first pop-in loads in nanoindentation to detect chemical short-range ordering in the equiatomic Cr-Co-Ni medium-entropy alloy Acta Mater. (IF 9.4) Pub Date : 2024-02-23 Le Li, Jun-Ping Du, Shigenobu Ogata, Haruyuki Inui
The variations of the first pop-in load in nanoindentation with annealing temperature and time have been investigated both by experiment and theoretical molecular dynamics (MD) simulations for the equiatomic Cr-Co-Ni medium-entropy alloy (MEA). Regardless of the loading rates, the first pop-in load tends to increase with the increase in electrical resistivity consistently by experiment and MD simulations
-
Revisiting the precipitation mechanisms of Guinier-Preston zones, η′, and η precipitates in Al-Zn-Mg alloys Acta Mater. (IF 9.4) Pub Date : 2024-02-23 Sha Liu, Huiying Hou, Wei Shao, Jian Yang, Zhijie Wang, Qingxiang Yang, Javier LLorca
Al-Zn-Mg alloys stand among the strongest Al alloys due to the interaction of Guinier-Preston (GP) zones and η′ precipitates with dislocations. Understanding the process of precipitate nucleation is critical to design age-hardenable Al-Zn-Mg alloys with improved mechanical properties. In this investigation, the structure and formation path of GP zones, η′ and η precipitates was studied by means of
-
An additively manufactured near-eutectic Al-Ce-Ni-Mn-Zr alloy with high creep resistance Acta Mater. (IF 9.4) Pub Date : 2024-02-22 Sumit Bahl, Tiffany Wu, Richard A. Michi, Ke An, Dunji Yu, Lawrence F. Allard, Jovid U. Rakhmonov, Jonathan D. Poplawsky, Chris M. Fancher, David C. Dunand, Alex Plotkowski, Amit Shyam
A new additively manufactured (AM) Al-7.5Ce-4.5Ni-0.4Mn-0.7Zr (wt.%) near-eutectic alloy is reported, which shows unprecedented creep resistance up to 400 °C (a homologous temperature of 0.72). The eutectic solidification microstructure comprises ∼ 27 vol% of coarsening-resistant second phase network with an ultrafine (<100 nm) inter-phase spacing. Both Mn and Zr contribute to creep resistance of the
-
Experimental study and modelling of carbide precipitation sequence in Fe based model alloys containing C, Mo and Mn. Acta Mater. (IF 9.4) Pub Date : 2024-02-22 A. Benarosch, C. Toffolon-Masclet, J.M. Joubert, B. Marini, E. Meslin, Z. Trzaska, D. Thiaudière, C. Mocuta, I. Guillot
In the context of the heat treatment optimisation of steels used for nuclear reactor pressure vessel, the carbide precipitations in three model alloys: Fe-0.2 %C-1 %Mn, Fe-0.2 %C-1.5 %Mo and Fe-0.2 %C-1 %Mn-1.5 %Mo have been experimentally investigated and modelled.
-
Underpinnings behind the magnetic order-to-disorder transition and property anomaly of disproportionated insulating samarium nickelate Acta Mater. (IF 9.4) Pub Date : 2024-02-21 Jinglian Du, Zilin Zhang, Shun-Li Shang, Ang Zhang, Yi Wang, Zi-Kui Liu, Feng Liu
Perovskite nickelates (RNiO), as benchmark materials for exploring underlying physics of phase transitions in strong correlated systems, are well-known for their rich structural characteristics and physicochemical properties. Understanding phase transition from the spin-ordered antiferromagnetic (AFM) state to the spin-disordered paramagnetic (PM) state of RNiO requires accurate models at finite temperatures
-
Decoding crystallization behavior of aluminoborosilicate glasses: From structural descriptors to Quantitative Structure – Property Relationship (QSPR) based predictive models Acta Mater. (IF 9.4) Pub Date : 2024-02-21 Yingcheng Zhang, Marco Bertani, Alfonso Pedone, Randall E. Youngman, Gregory Tricot, Aditya Kumar, Ashutosh Goel
Successful decoding of structural descriptors controlling the crystallization in multicomponent functional glasses can pave the way for the transition from the approach and empirical modeling for glass/glass-ceramic composition design toward more rational and scientifically rigorous Quantitative Structure-Property Relationship (QSPR) based models. However, due to the compositional and structural complexity
-
Mesophase induced by alternating-current poling in relaxor ferroelectric single crystals Acta Mater. (IF 9.4) Pub Date : 2024-02-21 Shuhao Wang, Zhen Liu, Lu Han, Xinrui Yang, Xingmin Zhang, Xiaolong Li, Lisha Liu, Dmitry Karpinsky, Turab Lookman, Haosu Luo, Jinglei Li, Fei Li, Yaojin Wang
Alternating-current poling (AC-Poling) has attracted wide interests in enhancing piezoelectric performance of ferroelectric single crystals. However, the mechanism of phase transformations and domain morphology underlying AC-Poling has not been thoroughly investigated. In this work, we have systematically studied the AC-poling effect on domain structures and piezoelectric properties in the relaxor
-
-
Alloy informatics through ab initio charge density profiles: Case study of hydrogen effects in face-centred cubic crystals Acta Mater. (IF 9.4) Pub Date : 2024-02-21 Dario Massa, Efthimios Kaxiras, Stefanos Papanikolaou
Materials design has traditionally evolved through trial-error approaches, mainly due to the non-local relationship between microstructures and properties such as strength and toughness. We propose ‘alloy informatics’ as a machine learning based prototype predictive approach for alloys and compounds, using electron charge density profiles derived from first-principle calculations. We demonstrate this
-
Quantifying free energies through local composition fluctuations in binary solid solutions: A proof-of-concept study using atomistic embedded-atom simulations Acta Mater. (IF 9.4) Pub Date : 2024-02-21 D. Bitter, M. Poul, G. Schmitz, S.M. Eich
While thermodynamic fluctuation theory has been extensively utilized in liquids for decades to obtain direct thermodynamic information, such as Gibbs free energies, from local composition fluctuations, this study presents an extension of the theory for its application in solids. It is demonstrated that composition fluctuations in solids are influenced by an additional elastic work term, which is specific
-
Direct observations of dynamic and reverse transformation of Ti-6Al-4V alloy and pure titanium Acta Mater. (IF 9.4) Pub Date : 2024-02-20 Baoqi Guo, Huicong Chen, Yan Chong, Wenqi Mao, Stefanus Harjo, Wu Gong, Zhongwu Zhang, John J. Jonas, Nobuhiro Tsuji
This paper focused on the characterization and mechanism of the dynamic transformation from the alpha to beta phase during the hot deformation of Ti-6Al-4V alloy and pure titanium. The investigation employed neutron diffraction and atomistic simulations for a comprehensive understanding of the process. Dynamic transformations were observed during deformation of the Ti-6Al-4V alloy and pure titanium
-
Evading strength-ductility trade-off dilemma in TRIP-assisted Fe50Mn30Co10Cr10 duplex high-entropy alloys via flash annealing and deep cryogenic treatments Acta Mater. (IF 9.4) Pub Date : 2024-02-20 Changshan Zhou, Zongde Kou, Kaikai Song, Jianhong Gong, Pingping Liu, Qingwei Gao, Xiaoming Liu, Xiaoliang Han, Zequn Zhang, Parthiban Ramasamy, Lina Hu, Jiri Orava, Jürgen Eckert
Conventional and multi-component alloys frequently compromise ductility to strike a balance between strength and ductility through intricate thermomechanical processes. Hence, it is essential to explore a straightforward and efficient approach to concurrently attain high strength and ductility. In this work, an ultrafast annealing-deep cryogenic treatment-tempering (UHDCT) method is proposed to significantly
-
Independent enhancement of the in-plane Seebeck effect in 2D PtSe2/PtSe2 homostructures via a facile interface tuning method Acta Mater. (IF 9.4) Pub Date : 2024-02-18 Min-Jeong Kim, Jung-Min Cho, Won-Yong Lee, Min-Sung Kang, Yun-Ho Kim, Gil-Sung Kim, Yumin Sim, Young-Gui Yoon, Maeng-Je Seong, Zhi-Bin Zhang, Sang-Kwon Lee
Atomically thin two-dimensional (2D) transition-metal dichalcogenide (TMDC) films have emerged as promising semiconducting materials for use in thermoelectric (TE) applications. However, the utilization of such materials remains challenging owing to the relatively high intrinsic resistance as the size of the TMDC thin films increases to the centimeter scale. These 2D TMDC films can also form vertically
-
Identifying the promising n-type SmMg2Sb2-based Zintl phase thermoelectric material Acta Mater. (IF 9.4) Pub Date : 2024-02-18 Zongwei Zhang, Juan Li, Honghao Yao, Qi Wang, Li Yin, Kejia Liu, Xiaojing Ma, Minhui Yuan, Ruoyu Wang, Sichen Duan, Xin Bao, Jinxuan Cheng, Xinyu Wang, Xiaofang Li, Jing Shuai, Jiehe Sui, Xi Lin, Xiaojian Tan, Xingjun Liu, Jun Mao, Guoqiang Xie, Qian Zhang
The discovery of promising thermoelectric materials has often been challenged by the doping bottleneck. As an example, the n-type Zintl phases are promising thermoelectric materials but are challenging to synthesize due to intractable cation vacancies. In this work, by incorporating excess Mg and Te doping, n-type SmMgSb with high thermoelectric performance has been realized. Density functional theory
-
Quantifying phase mixing and separation behaviors across length and time scales Acta Mater. (IF 9.4) Pub Date : 2024-02-17 M. Skolnick, S. Torquato
Phase mixing and separation phenomena abound in the formation of natural and synthetic material systems, including alloys, composites, granular media, geological media, complex fluids, and biological media. While characterizing phase mixing is critical to understanding material microstructure formation and physical properties, previous metrics that measure the degree of mixing in condensed phases often
-
A strong-yet-ductile high-entropy alloy in a broad temperature range from cryogenic to elevated temperatures Acta Mater. (IF 9.4) Pub Date : 2024-02-17 Y.H. Zhou, J.Y. Zhang, J. Zhang, X.Y. Yao, J.H. Luan, Q. Li, S.F. Liu, B. Xiao, J. Ju, S.J. Zhao, Y.L. Zhao, Z.Y. Sun, H. Nan, M. Yan, T. Yang
Developing strong-yet-ductile alloys with wide temperature capabilities is crucial for modern industrial and scientific applications; however, this is often difficult to realize using conventional wisdom. In this work, we innovatively designed a nanoparticle-strengthened high-entropy alloy (HEA) through elaborate compositional design and thermomechanical regulation. The designed HEA exhibits extraordinary
-
Atom probe tomography-assisted kinetic assessment of spinodal decomposition in an Al-12.5 at.%Zn alloy Acta Mater. (IF 9.4) Pub Date : 2024-02-16 Xinren Chen, Xuyang Zhou, Frédéric De Geuser, Alisson Kwiatkowski da Silva, Huan Zhao, Eric Woods, Chuanlai Liu, Dirk Ponge, Baptiste Gault, Dierk Raabe
The rates of atomic clustering and precipitation hardening are closely related to the diffusivity of solutes and the concentration of vacancies during the natural aging of aluminum alloys. The measurement of the diffusivity of solutes at room temperature, especially in systems with an equilibrium vacancy concentration, is beneficial to the design of the aging process. However, this measurement has