Article
Materials Science, Multidisciplinary
Yujiao Li, Shoji Goto, Aleksander Kostka, Michael Herbig
Summary: The strength of pearlitic wires can be increased to a world record level of 7 GPa through cold-drawing. Using nano-beam diffraction, the microstructure of the wires was directly probed, revealing the significance of high-angle grain boundaries and geometrically necessary dislocations in the strengthening mechanism.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
Wyatt A. Witzen, McLean P. Echlin, Marie-Agathe Charpagne, Tresa M. Pollock, Irene J. Beyerlein
Summary: This study investigates the intragranular distributions of geometrically necessary dislocations (GNDs) in a polycrystalline tantalum sample under shock compression loading. Using TriBeam tomography, a highly resolved 3D map of the microstructure was obtained, allowing for the examination of grain boundaries, orientations, and voids. By combining the 3D characterization, GND formulation, and a sample with approximately 6000 grains, correlations between GND density per grain and grain characteristics were analyzed. The results show that GND density increases closer to the spall plane and that grains containing voids have high GND density concentrations in the intragranular region surrounding the void.
Article
Nanoscience & Nanotechnology
Qinan Han, Xusheng Lei, Hao Yang, Xiaolin Yang, Zimu Su, Shao-Shi Rui, Nan Wang, Xianfeng Ma, Haitao Cui, Huiji Shi
Summary: This paper investigates the effects of temperature and load on the distribution of geometrically necessary dislocation (GND) induced by fretting fatigue in titanium alloy. The results show that both temperature and load have significant effects on GND densities, with an increase in temperature and load leading to a rise in GND densities. The peak positions of GND density correspond well with crack formation locations, indicating a close relationship between GND concentration and fretting fatigue crack formation.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Jing-Hua Zheng, Catalin Pruncu, Kai Zhang, Kailun Zheng, Jun Jiang
Summary: This study provides direct and systematic experimental data by revealing the evolution of dislocation density and grain size of AA6082 alloy under different conditions, using Electron Back Scattering Diffraction (EBSD) technique. The results show continuously increased geometrically necessary dislocation densities during hot deformation, as well as the presence of dislocation channel structures and dynamic recrystallization. The study is the first to visualize high temperature and high strain rate induced dislocation distributions over a relatively large area, offering valuable insights for improving physically based material models.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Kai Zhang, Xinbao Liu, Ping Fan, Lin Zhu, Kai Wang, Lin Wang, Caili Zhao
Summary: This study investigates the change of geometrically necessary dislocation (GND) during the elevated temperature creep of P91 steel. The results show that the GND density increases significantly during the initial creep stage, reaches a maximum at the transition from initial creep to steady creep, and gradually decreases during subsequent creep. It also demonstrates that the GND density can be used to predict internal stress and analyze microstructure degradation of P91 steel during creep.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
Mohammed Mendas, Stephane Benayoun, Mohamed Hadj Miloud, Ibrahim Zidane
Summary: This study extends the analysis of the indentation size effect (ISE) to lamellar cast irons, demonstrating that the tensile model and the concept of geometrically necessary dislocations (GNDs) can be used to predict the ISE of the pearlitic matrix within these materials. The summation of stresses associated with GNDs and statistically stored dislocations (SSDs) is shown to be more adequate in the prediction of ISE compared to considering only one work-hardening stress.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Materials Science, Multidisciplinary
Yan Chong, Tomohito Tsuru, Baoqi Guo, Reza Gholizadeh, Koji Inoue, Nobuhiro Tsuji
Summary: In this study, the influences of nitrogen content and grain size on the tensile properties and deformation behaviors of titanium at room temperature were systematically investigated. Ultrafine-grained (UFG) Ti-0.3 wt%N alloy with a fully recrystallized microstructure was obtained, exhibiting unprecedented ultrahigh yield strength and large uniform elongation. The hardening and strain-hardening mechanisms of Ti-0.3 wt%N alloy were comprehensively studied, revealing the dual contributions of nitrogen to the excellent strength/ductility balance in UFG Ti-0.3 wt%N.
Article
Nanoscience & Nanotechnology
Nan Wang, Yongnan Chen, Gang Wu, Qinyang Zhao, Zhen Zhang, Lixia Zhu, Jinheng Luo
Summary: This study reveals the different contributions of geometrically necessary dislocation (GND) and statistically stored dislocation (SSD) to work hardening in dual-phase steel. By introducing high-density GND through pre-tensile loading-unloading-reloading (LUR) and high-density SSD through monotonic pre-tensile, it is found that the steel with high GND exhibits higher yield stress and stronger strain hardening ability compared to the high-SSD steel, even with almost the same total dislocation density.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Jin Wang, Likang Luan, Tillmann Volz, Sabine M. Weygand, Ruth Schwaiger
Summary: Wedge indentation experiments on single-crystalline tungsten revealed the depth dependence of geometrically necessary dislocation structures, showing the evolution of dislocation structures at different depths.
JOURNAL OF MATERIALS RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Akbar Heidarzadeh, Roghayeh Mohammadzadeh, Hamid Reza Jafarian, Catalin Iulian Pruncu, Aude Simar
Summary: The study reveals the contribution of GNDs and GBs to the mechanical properties of different zones in a friction stir welded pure copper joint, with higher GNDs density in the weld. Differences among zones are mainly related to the distribution of dislocations.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Mechanical
Yilun Xu
Summary: A non-local method for establishing GND based on a non-local domain integral has been developed and validated, showing improved accuracy in predicting material fatigue life. The comprehensive study on non-local domain effect revealed the necessity of applying the non-local GND method, as it resembles experimental observations and enhances stress field predictions compared to local methods.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Engineering, Mechanical
Songjiang Lu, Qianhua Kan, Michael Zaiser, Zhenhuan Li, Guozheng Kang, Xu Zhang
Summary: This study examines the effects of grain size and dislocation source properties on the yield stress of ultrafine-grained polycrystals using three-dimensional multiscale discrete dislocation dynamics. The simulation demonstrates a nonmonotonic dependency of flow stress on dislocation source length and deviations from the classical Hall-Petch relationship in the grain size dependence of yield stress. The study provides insights into the controlling factors of yield stress in the ultrafine-grained regime and proposes a theoretical model to explain the combined effects of source length, grain size, and initial dislocation density.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Nanoscience & Nanotechnology
Yan Long, Kebo Liao, Xiaolong Huang
Summary: The study found the formation of dynamic recrystallization-induced micro shear bands in an ultrafine-grained Ti-6Al-4V alloy under quasi-static compression. The localized strain regions experienced a two-step recrystallization process, resulting in refined DRX grains and nanograins. Micro shear bands nucleated, widened, multiplied, and propagated with increasing local strains.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Hongxing Li, Si Gao, Yo Tomota, Seiichiro Ii, Nobuhiro Tsuji, Takahito Ohmura
Summary: This study investigates the motion of dislocations and their interactions with grain boundaries in ultrafine-grained IF steel under tensile and compressive conditions. Before macro-yielding, dislocations move towards grain boundaries and are absorbed, leading to a decrease in dislocation density; after macro-yielding, dislocations emit from grain boundaries, resulting in hardening effects and discontinuous yielding behavior.
Review
Chemistry, Multidisciplinary
Lin Zhang, Xingyu Li, Xuanhui Qu, Mingli Qin, Zhongyou Que, Zichen Wei, Chenguang Guo, Xin Lu, Yanhao Dong
Summary: Ultrafine-grained (UFG) refractory metals are promising materials for various applications, but achieving full density while maintaining a fine microstructure through sintering remains challenging. This article provides an overview of sintering issues, microstructural design rules, and powder metallurgy practices for UFG and nanocrystalline refractory metals. It also reviews previous efforts, including the use of fine/nanopowders and field-assisted sintering techniques, and highlights the recent technological breakthrough of pressureless two-step sintering for producing dense UFG refractory metals. Additionally, the progress of powder metallurgy in specific materials systems, such as elementary metals and refractory alloys, is discussed, and future developments towards UFG and nanocrystalline refractory metals with improved properties are outlined.
ADVANCED MATERIALS
(2023)
Review
Materials Science, Multidisciplinary
M. Seifi, I. Ghamarian, P. Samimi, P. C. Collins, N. J. H. Holroyd, J. J. Lewandowski
Article
Materials Science, Multidisciplinary
Michael Y. Mendoza, Maria J. Quintana, Peter C. Collins
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2020)
Article
Materials Science, Multidisciplinary
Maria J. Quintana, Matthew J. Kenney, Priyanka Agrawal, Peter C. Collins
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2020)
Article
Chemistry, Physical
Xinyi Gong, Yuksel C. Yabansu, Peter C. Collins, Surya R. Kalidindi
Correction
Materials Science, Multidisciplinary
Maria J. Quintana, Matthew J. Kenney, Priyanka Agrawal, Peter C. Collins
Summary: The original article is missing the following content from the Acknowledgments.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Peter C. Collins, D. Gary Harlow
Summary: Additive manufacturing of titanium with electron beam exhibits significant variability, requiring consideration of geometry and microstructure in predicting material properties. The goal of integrated modeling and statistical analysis is to characterize yield stress, especially in the critical lower tail for high reliability estimation and prediction. Methodology for calibration of yield stress distribution function using experimental data is applied to manage uncertainty and improve estimation.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2021)
Article
Nanoscience & Nanotechnology
Matthew J. Kenney, Katie O'Donnell, Maria J. Quintana, Peter C. Collins
Summary: This study investigates the characteristics and formation mechanisms of gas pores in additive manufacturing, specifically in Electron Beam Melted Ti-6Al-4V. The presence of large spherical pores exclusively in raster scan suggests perturbations caused by elastic instabilities from chemical and crystallographic variations. The findings provide insights into the physics of defects in the AM process.
SCRIPTA MATERIALIA
(2021)
Article
Microscopy
Ryan DeMott, Nima Haghdadi, Charlie Kong, Ziba Gandomkar, Matthew Kenney, Peter Collins, Sophie Primig
Summary: 3D electron backscatter diffraction (3D-EBSD) is a method for obtaining 3-dimensional crystallographic data through serial sectioning. Recent advances in using Xe+ plasma focused ion beam for sectioning, along with a metal-oxide semiconductor based EBSD detector, have improved the balance between volume analyzed and spatial resolution. This method has been applied to studying microstructural phenomena in Ti6Al-4V microstructures, where new algorithms have been developed for 3D data reconstruction and analysis.
Article
Chemistry, Physical
Noah J. Welch, Maria J. Quintana, Todd M. Butler, Peter C. Collins
Summary: This study investigates the microstructures and oxidation behavior of TaTiCr, Ta4Ti3Cr, Ta2TiCr, and Ta4TiCr3 concentrated refractory alloys, and reveals the effect of moderate composition changes on oxidation performance. The TaTiCr alloy demonstrates superior oxidation resistance, while Ta4TiCr3 shows moderate resistance, and Ta4Ti3Cr and Ta2TiCr exhibit poor performance. The excellent oxidation performance of TaTiCr can be attributed to the compact, continuous oxide scale, the formation of complex oxides and protective Cr2O3, and the presence of complex internal nitride morphology.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Katie O'Donnell, Maria J. Quintana, Peter C. Collins
Summary: Research on additive manufacturing of metals often ignores the composition of the final parts. This study investigates the composition of electron-beam-melted Ti-6Al-4V produced through different scanning strategies. The results show that varying scanning strategies lead to different composition and significant changes in the material's properties.
Article
Engineering, Manufacturing
Maria J. Quintana, Andrew J. Temple, D. Gary Harlow, Peter C. Collins
Summary: This paper presents a phenomenological approach to predict the plastic regime of stress-strain curves using a limited number of parameters. Experimental studies were conducted on both conventionally processed and additively manufactured Ti-6Al-4V, validating the effectiveness of this approach. The predicted ultimate tensile strengths were within 5% of the experimentally measured values.
INTEGRATING MATERIALS AND MANUFACTURING INNOVATION
(2022)
Article
Materials Science, Multidisciplinary
Maria J. Quintana, Katie O'Donnell, Matthew J. Kenney, Peter C. Collins
ADVANCED MATERIALS & PROCESSES
(2021)
Article
Microscopy
Ryan DeMott, Peter Collins, Charlie Kong, Xiaozhou Liao, Simon Ringer, Sophie Primig
Article
Chemistry, Multidisciplinary
Michael Y. Mendoza, Peyman Samimi, David A. Brice, Iman Ghamarian, Matt Rolchigo, Richard LeSar, Peter C. Collins
Article
Materials Science, Characterization & Testing
Lucas W. Koester, Hossein Taheri, Timothy A. Bigelow, Peter C. Collins, Leonard J. Bonds
MATERIALS EVALUATION
(2018)
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.