Article
Materials Science, Multidisciplinary
Rui Yue, Lingyu Li, Ziyu Li, Jinpeng Zhang
Summary: In this paper, a pure zinc sample was prepared by extrusion at room temperature and its microstructure evolution during tensile testing was studied. The extruded zinc exhibited excellent ductility and its stress increased first and then decreased when the strain was more than 20%. The main deformation mechanisms were dislocation slip and dynamic recrystallization.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Materials Science, Ceramics
Shuai Wang, Xianjuan Pang, Zhiyuan Zhang, Baolin Chang, Jun Yang, Chenfei Song, Sanming Du, Yongzhen Zhang
Summary: Single-phase polycrystalline Mo2BC ceramic bulks were successfully synthesized using spark plasma sintering method at a low synthesis temperature of 1300 degrees C. The ceramic exhibited high Vickers hardness and typical brittle features, with intergranular and transgranular fractures as the main failure modes.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Nanoscience & Nanotechnology
Rongkai Tan, Zhanfeng Wang, Shilei Wu, Weili Liu, Beibei Jiang
Summary: In this study, the influence of crystallographic orientation on the nanoindentation behavior of polycrystalline copper was investigated through experiments and finite element simulations. The results showed a high degree of anisotropy in the indentation behavior due to different slip systems for different crystallographic orientations, leading to different mechanical responses and distinct material pileup morphologies. Furthermore, it was found that crystallographic orientation plays a critical role in determining the indentation size effect.
Article
Materials Science, Multidisciplinary
Zhanfeng Wang, Xiao Liu, Shilei Wu, Weili Liu, Ran Yang, Beibei Jiang
Summary: The deformation behavior of crystalline materials is affected by microstructural characteristics. This study focuses on the effects of crystallographic orientation and grain boundary on the mechanical properties of polycrystalline copper using nanoindentation experiments and crystal plasticity finite element simulations. A crystal plasticity constitutive model with geometrically necessary dislocations is developed to simulate the indentation mechanical response. The results reveal significant anisotropy in the indentation behavior of polycrystalline copper, attributed to variations in the distributions of statistically stored dislocations and geometrically necessary dislocations. Additionally, the grain boundary plays a crucial role in determining the anisotropy and indentation size effect. These findings offer insights for the design of materials for plasticity applications.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Ceramics
Wenhao Dai, Shuai Zhang, Jianbo Tu, Xueqi Wang, Chuang Zhao, Baochang Liu
Summary: This study investigated the effect of grain size on wear behavior while cutting dense granite using polycrystalline diamond compact (PDC) with different grain sizes. The results showed that coarse grade PDC had higher impact resistance and fracture toughness, while fine grade PDC had higher cobalt content, hardness and thermal resistance. The wear resistance changed in the same way as thermal expansion properties, indicating a strong correlation. Thermal mismatch-induced crack network and peeling/fracture of metallic phases and diamond played critical roles in the wear of coarse grade PDC.
CERAMICS INTERNATIONAL
(2023)
Article
Physics, Applied
Xiaoshuang Liu, Rong Wang, Junran Zhang, Yunhao Lu, Yiqiang Zhang, Deren Yang, Xiaodong Pi
Summary: Anisotropic deformation and mechanical properties of 4H silicon carbide (4H-SiC) single crystal wafers were investigated using nanoindentation. The C face of the wafer exhibited higher hardness and lower fracture toughness compared to the Si face. The deformation mechanism was found to be assisted by the nucleation and slip of basal plane dislocations (BPDs) and the nucleation and slip of Si-core partial dislocations (PDs) in the Si face were easier than in the C face, leading to changes in the hardness and fracture toughness of the Si face. The insights gained from this study are expected to be valuable for optimizing the mechanical processing of 4H-SiC wafers.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Metallurgy & Metallurgical Engineering
Yan-qiu ZHANG, Shu-yong JIANG
Summary: Through MD simulation, it was found that nanotwinned polycrystalline copper with {111} texture exhibits hard and soft orientations during tensile deformation, each involving distinct dislocation mechanisms. The strengthening mechanism of hard orientation is attributed to interactions between dislocations and twin boundaries, while the softening mechanism of soft orientation is due to the lack of interaction between dislocations and twin boundaries.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2021)
Article
Materials Science, Multidisciplinary
Xueqi Wang, Jianbo Tu, Wenhao Dai, Pinwen Zhu, Qiang Tao, Fulong Ning, Baochang Liu
Summary: In this study, fine-grained polycrystalline diamond compacts (PDC) doped with 0.5 wt% nano-vanadium carbide (VC) were sintered under high pressure and high temperature. The addition of VC improved the hardness, impact resistance, and wear resistance of the PDC samples. This improvement can be attributed to the occupation of cobalt space by the harder material VC, the reduction of cobalt and eta-phase Co3W3C content, and the refinement and dispersion of tungsten carbide (WC) grains.
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Zahabul Islam, Christopher M. Barr, Khalid Hattar, Aman Haque
Summary: The study explores the interaction of electron wind force with defects from ion irradiation in-situ within a transmission electron microscope. It was found that the electron wind force can significantly enhance defect mobility even at low temperatures, leading to defect migration and elimination within a few minutes. This interaction creates highly glissile Shockley partial dislocations, enabling fast and low temperature defect annihilation.
Article
Materials Science, Multidisciplinary
Tong Wu, Qiuguang Zhang, Hang Lu, Yuhao Shi, Qianrun Zhang, Shuye Zhang, Ruiqi Wang, Panpan Lin, Tiesong Lin, Peng He
Summary: The effects of bonding temperature and time on the microstructure and mechanical properties of the joint between IC10 single crystal superalloy and GH536 polycrystalline superalloy were investigated. Lower temperature and time resulted in the formation of hard borides, leading to lower shear strength.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Hua-Yue Liang, Ji Zou, Jing-Jing Liu, Yi-Han Gu, Wei Ji, Zi-Han Wang, Wei-Min Wang, Zheng-Yi Fu
Summary: Tunable anisotropic physical and mechanical properties were achieved in conductive ceramics by incorporating hBN flakes, providing new opportunities for material selection and design.
SCIENCE CHINA-MATERIALS
(2023)
Article
Chemistry, Physical
Yang Liu, Lei Wang, Kaiyue Yang, Xiu Song
Summary: The high cycle fatigue properties of IN718 alloy treated by warm laser shock processing (WLSP) after high-temperature ageing were investigated. The strengthening and toughening mechanism of WLSP on the hardened surface layer of IN718 alloy was revealed, showing highly stable strengthening effects at high temperature. WLSP demonstrated superior fatigue resistance and prolonged fatigue life for the alloy under long-term elevated temperature service compared to conventional laser shock peening (LSP).
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
Dongsheng He, Liuhe Li, Jiaxuan Chi, Hepeng Zhang, Gongxuan Zhang, Guangzhi He, Jianfeng Yan, Hongqiang Zhang, Wei Guo
Summary: Ti2AlNb alloy is a new lightweight and heat-resistant structural material with improved mechanical properties. Laser shock peening (LSP) was used to investigate the microstructure response of different phases in the alloy. The study found that the highest density of dislocations was generated in the B2/beta phases, followed by the O phases, and the least dislocations were observed in the alpha 2 phases. Dislocation structures, stacking faults, mechanical twins, and dislocation cells were observed, which contributed to the refinement of the microstructure and improved hardness and residual stress distribution.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Chemistry, Physical
Xingshuai Zheng, Tengfei Sun, Jixing Zhou, Rupeng Zhang, Pingmei Ming
Summary: This paper presents a new implementation of Voronoi diagram in Laguerre geometry for generating numerical models of polycrystalline microstructures. The method allows control over grain size and shape, and the modeling of 3D grain boundaries with specified thickness. The distribution of grain sizes in the models is fitted to a lognormal distribution instead of the normal distribution in traditional Voronoi tessellation methods. Statistical analyses and simulations are conducted to verify the effectiveness of the proposed method in modeling polycrystalline ceramic materials.
Article
Multidisciplinary Sciences
Zhengkai Wu, Shengchuan Wu, Xi Gao, Ying Lin, Yanling Xue, Philip J. Withers
Summary: This study investigates the effects of defects on tensile failure of additive manufactured AlSi10Mg alloy, with a focus on large pancake shaped loss of fusion (LOF) defects lying perpendicular to the build direction (BD). The results show that when tested parallel to the BD, LOF defects lead to low plasticity and brittle failure, while when aligned edge-on to the straining direction, the defects exhibit ductile failure with significant elongation and necking. The findings emphasize the importance of minimizing the size and aspect ratio of LOF defects to control tensile ductility.
SCIENTIFIC REPORTS
(2023)
Article
Engineering, Mechanical
Jisheng Qin, Bjorn Holmedal, Odd Sture Hopperstad
INTERNATIONAL JOURNAL OF PLASTICITY
(2019)
Article
Engineering, Mechanical
K. Zhang, B. Holmedal, T. Manik, A. Saai
INTERNATIONAL JOURNAL OF PLASTICITY
(2019)
Article
Engineering, Mechanical
Bjorn Holmedal
INTERNATIONAL JOURNAL OF PLASTICITY
(2019)
Article
Materials Science, Multidisciplinary
Siri Marthe Arbo, Tina Bergh, Bjorn Holmedal, Per Erik Vullum, Ida Westermann
Article
Multidisciplinary Sciences
Emil Christiansen, Calin Daniel Marioara, Bjorn Holmedal, Odd Sture Hopperstad, Randi Holmestad
SCIENTIFIC REPORTS
(2019)
Article
Materials Science, Multidisciplinary
Eva Anne Mortsell, Ida Westermann, Calin Daniel Marioara, Ketill Olav Pedersen, Sigmund Jarle Andersen, Jostein Royset, Bjorn Holmedal, Randi Holmestad
Article
Materials Science, Multidisciplinary
Bjorn Holmedal
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2020)
Article
Crystallography
Bjorn Holmedal
Article
Engineering, Multidisciplinary
T. Manik, H. M. Asadkandi, B. Holmedal
Summary: A new stable return-mapping algorithm is proposed for crystal-plasticity solutions, which uses a regularized yield surface with very large exponents. The algorithm achieves good numerical stability and is implemented as a fast and stable implicit method in finite element software for simulations of both single crystals and polycrystalline materials.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Sohail Shah, Akash Gopal, Elisabeth Thronsen, Constantinos Hatzoglou, Bjorn Holmedal
Summary: Comparison between natural and artificial ageing treatments with cyclic deformation ageing at room temperature revealed different fracture behaviors and mechanical responses for Al-Zn-Mg alloys. Cyclic ageing resulted in early slant shear fracture, while natural ageing improved mechanical properties.
MATERIALS & DESIGN
(2022)
Article
Nanoscience & Nanotechnology
Jianbin Xu, Lei Liu, Odd Sture Hopperstad, Bjorn Holmedal, Tomas Manik, Knut Marthinsen
Summary: In this study, a novel method is proposed to quantitatively analyze localized deformation bands exhibiting the Portevin-Le Chatelier effect. The method introduces a multi-strain-jump function to capture the experimentally obtained strain profile. The approach allows for automatic extraction of band strain and enables the linking of band characteristics with local material properties.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Christoph M. Hell, Bjorn Holmedal, Ruben Bjorge, Calin D. Marioara, Randi Holmestad
Summary: In this study, the origin of a double-peak during artificial aging of an EN-AW 6082 is analyzed using (S)TEM. The TEM data is used in a strength model to explore the origin and broader strength plateau of the double-peak. It is concluded that the first peak is caused by wide and high-density p-type precipitates, while the second peak is due to a broader size distribution of precipitates of the same type. The second peak is maintained by long precipitates of a hybrid type with overaged phases, counteracting the strength loss from Ostwald ripening.
Article
Materials Science, Multidisciplinary
E. Thronsen, S. Shah, C. Hatzoglou, C. D. Marioara, S. Wenner, S. J. Andersen, B. Holmedal, R. Holmestad
Summary: The evolution of early-stage precipitates in a 7003 aluminium alloy was investigated through artificial ageing. It was found that after 10 minutes of artificial ageing, the hardness of the precipitates decreased and their size increased, indicating the dissolution of the Guinier-Preston (GP) zones. Subsequently, as the ageing time increased, the hardness gradually increased and new precipitate phases appeared. Atomically resolved scanning transmission electron microscopy images of the disputed T' phase were also presented.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Qiang Du, Lina Jia, Kai Tang, Bjorn Holmedal
Article
Materials Science, Multidisciplinary
Yue Li, Bjorn Holmedal, Hongxiang Li, Linzhong Zhuang, Jishan Zhang, Qiang Du