Article
Materials Science, Multidisciplinary
Abbas Mohammadi, Nariman A. Enikeev, Maxim Yu Murashkin, Makoto Arita, Kaveh Edalati
Summary: The study achieved nanograin sizes in an Al-La-Ce alloy through ultra-SPD followed by aging, and identified two breaks in the Hall-Petch relationship. Detailed analysis confirmed that nanograin formation alone is not sufficient for extra hardening, and additional strategies such as grain-boundary segregation and precipitation are necessary to address the issue of softening.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Physical
Yifan Bu, Xiuzhen Zhang, Dengshan Zhou
Summary: Experimental observations show that the strain dependence of the Hall-Petch slope in Al-Mg alloys is significantly influenced by the formation of Laders bands and the Mg content. The Hall-Petch slope initially drops due to Laders deformation, then increases with plastic strain until reaching its maximum, and subsequently decreases due to dynamic recovery. Alloys with higher Mg contents exhibit a larger Hall-Petch slope at a given strain, and their dynamic recovery is postponed until a larger strain is reached. Interestingly, a model developed for low stacking fault energy materials accurately describes the relationship between the Hall-Petch slope, Mg content, and strain magnitude.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Quanfeng Han, Xin Yi
Summary: As the average grain size decreases, the reduction in intragranular dislocation storage ability is revealed as the underlying mechanism of the breakdown of Hall-Petch behavior in nanocrystalline (NC) metals. The prediction of the critical grain size for the HP-inverse HP transition of NC metals agrees well with experimental results, showing remarkable ductility enhancement in the inverse HP region dominated by harmonized deformation of grain boundaries and grain interior. Additionally, the increase in grain boundary strength leads to enhancement in yield strength and delay in occurrence of the inverse HP behavior in NC metals.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
Jing Xu, Bo Guan, Yunchang Xin, Xuedong Wei, Guangjie Huang, Chenglu Liu, Qing Liu
Summary: In this study, a weak texture dependence of Hall-Petch slope (k) in a rare-earth containing Mg-2Zn-1Gd plate was reported, with similar k values for TD-tension and RD-tension. This characteristic can be well predicted by the compound use of activation stress difference and geometric compatibility factor, attributing the mechanism to the activation of a high fraction of additional deformation mode.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Ziyi Cui, Shudong He, Jie Tang, Dingfa Fu, Jie Teng, Fulin Jiang
Summary: Grain size has a significant impact on the mechanical properties and deformation behavior of twinning-induced plasticity (TWIP) steels. Larger grain size promotes twinning, resulting in a noticeable TWIP effect and a suppression of dislocation proliferation. The combination of dislocation strengthening and twinning leads to a long plateau in the work-hardening rate curve, increasing the work-hardening ability. Uniform distribution of strain at grain boundaries and twin boundaries improves plasticity by relieving stress concentration.
Article
Materials Science, Multidisciplinary
Xiaorong Liu, Sihan Jiang, Jianlin Lu, Jie Wei, Daixiu Wei, Feng He
Summary: Grain size plays a critical role in the strain hardening behaviors of high entropy alloys (HEAs) by affecting twinning-induced plasticity and dislocation-based deformation. Increasing grain size leads to a transition of dislocation glide mode and influences strain hardening rate. These findings have important implications for understanding the strain hardening behaviors in other face-centered-cubic HEAs.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Kai Yao, Xiaohua Min
Summary: This study investigated the effect of grain size on the tensile properties of Ti-15Mo alloy, revealing that the impact decreased with increasing strain and eventually became negative. A dynamic Hall-Petch relation was established based on effective grain size, showcasing twin activation, twin suppression, and various interactions.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Matias Bordone, Juan Perez-Ipina, Raul Bolmaro, Alfredo Artigas, Alberto Monsalve
Summary: This article focuses on the mechanical behavior and microstructural changes observed in two high-manganese steels with different carbon contents, impacting the TWIP and TRIP effects. Tensile tests revealed distinct fracture micro-mechanisms in the two steels.
Article
Nanoscience & Nanotechnology
Tian-Ren Yang, Yu-Hao Li, Qing-Yuan Ren, Dmitry Terentyev, Hong-Xian Xie, Ning Gao, Hong-Bo Zhou, Fei Gao, Guang-Hong Lu
Summary: Using molecular dynamics simulations, it was found that the aggregation of Rhenium (Re) on dislocation loops affects the interaction with edge dislocations. Particularly, for parallel loop cases, Re-decorated loops become strong obstacles for edge dislocation gliding compared to pure loops or Re-rich clusters. This synergetic pinning effect is dependent on the Re concentration and becomes prominent once Re exceeds a certain critical concentration. The coupling of Re with dislocation loops in tungsten (W) hinders the glide of edge dislocations and greatly contributes to irradiation hardening.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Leo Thiercelin, Francis Praud, Fodil Meraghni, Eric Fleury
Summary: In this study, a new constitutive model is proposed to explain the thermally-activated hardening recovery mechanism in metallic materials. The model incorporates the concept of hardening recovery variable and includes high temperature dependencies for both elastic and viscoplastic properties. Experimental data from uni-axial tests on AISI 316L austenitic stainless steel at various temperatures and strain rates are used to validate the model, and additional experimental data shows good agreement with the simulated responses, demonstrating the predictive capabilities of the model.
MECHANICS OF MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Haoran Lu, Pengfei Ji, Bo Li, Wei Ma, Bohan Chen, Xing Zhang, Xinyu Zhang, Mingzhen Ma, Riping Liu
Summary: In this study, a beta-type titanium alloy with excellent mechanical properties was designed using the molybdenum equivalence approach and Bo-Md map. The alloy exhibited high uniform elongation, yield strength, and stable intervals with high work-hardening rates. The investigation of deformation mechanisms revealed the significant influence of twinning-induced plasticity effects and dislocation slips on the alloy's work-hardening behavior.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Wang Cai, Chunhui Wang, Chaoyang Sun, Lingyun Qian, M. W. Fu
Summary: This study investigated the microstructure evolution and fracture behaviors of TWIP steel at different strain rates, revealing the competition between twinning and dislocation slip, as well as the dynamic mechanical properties of TWIP steel at high strain rates.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Kai Hu, Jun Yi, Bo Huang, Gang Wang
Summary: The mechanism of grain-size dependence on dislocation source-limited hardening and ductilization is still unknown. This study systematically investigated the effect of grain size on these processes in bulk pure Ni samples ranging from -20 nm to -20 pm. The results showed that high-density nano-twinning in the nanograined samples exhibited better thermodynamic stability and led to fine recrystallized grains with low-density dislocations. This work provides a new approach to obtain stronger and more ductile metallic materials through grain-size dependent dislocation source-limited hardening and ductilization.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Zhuocheng Xie, Dimitri Chauraud, Achraf Atila, Erik Bitzek, Sandra Korte-Kerzel, Julien Guenole
Summary: Synchro-Shockley dislocations, as zonal dislocation, play a crucial role in the plasticity of Laves phases at high temperatures. The motion of these dislocations involves localized transition events, and their activation volumes contribute to the temperature and strain rate sensitivity of the Peierls stress. However, the thermally activated behavior of synchro-Shockley dislocation motion is not well understood. This study investigates the transition mechanisms of these dislocations at different shear and normal strain levels, and reveals that the motion of synchro-Shockley dislocations is sensitive to shear, but requires thermal assistance for shear-insensitive events, indicating their inhibition at low temperatures.
SCRIPTA MATERIALIA
(2023)
Article
Nanoscience & Nanotechnology
Qing-Yuan Ren, Yu-Hao Li, Ning Gao, Wei-Zhong Han, Yu-Ze Niu, Hong-Xian Xie, Ying Zhang, Fei Gao, Guang-Hong Lu, Hong-Bo Zhou
Summary: The irradiation hardening caused by helium (He) ion bombardment is directly related to the pinning effect of He-related defects on dislocation glide in metals. Both nanoscale He bubbles and invisible He clusters play a critical role in He-irradiation hardening.
SCRIPTA MATERIALIA
(2022)
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.