Article
Materials Science, Multidisciplinary
Yu Liu, Jinglian Du, Shunli Shang, Ang Zhang, Shoumei Xiong, Zi-Kui Liu, Feng Liu
Summary: In this paper, the plastic deformation mechanisms of austenitic steels with different carbon (C) additions were investigated by coupling the generalized stacking fault energy (GSFE) with the semi-discrete variational Peierls-Nabarro (P-N) model. The positions and contents of C atoms were found to affect the GSFE of austenite, and thus regulate plastic deformation behaviors by influencing dislocation core structure. The investigation establishes a solid foundation for clarifying the plastic deformation mechanisms of austenitic steels from the perspective of the dislocation core structure.
PROGRESS IN NATURAL SCIENCE-MATERIALS INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Xue-Chun Zhang, Shuo Cao, Rui Yang, Qing-Miao Hu
Summary: The Peierls stress of FCC structures calculated using the PN model is highly sensitive to various input parameters, such as shear modulus, Poisson's ratio, and generalized stacking fault energy. This sensitivity leads to significant oscillations in the predicted Peierls stress. In this study, we propose a modified model that alleviates the sensitivity of the Peierls stress on the input parameters, resulting in better agreement with experimental values.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Multidisciplinary Sciences
Brook J. Hocking, Helen S. Ansell, Randall D. Kamien, Thomas Machon
Summary: By analyzing the topology of the ground state manifolds (GSMs) of density wave systems, it has been found that dislocations split into disclinations, and these disclinations are constrained to sit at specific phase values, resulting in an energy barrier to dislocation glide.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Nanoscience & Nanotechnology
Wei Jiang, Xuzhou Gao, Yazhou Guo, Xiang Chen, Yonghao Zhao
Summary: In this study, the dynamic impact behavior and deformation mechanisms of a Cr26Mn20Fe20Co20Ni14 high-entropy alloy were systematically explored. The alloy exhibited uniform plastic deformation and a significant strain rate dependence in yield strength. Microstructural analyses revealed a transition in deformation mechanisms and interactions between different dislocations, stacking faults, and twins in strengthening the material. This work provides a comprehensive understanding of the high-entropy alloy's behavior and strengthening mechanisms.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Yong-Xing Zhao, Yuan-Chun Huang, Yu Liu
Summary: Dislocation and thermodynamic properties of L1(2)-Al3X(X=Sc, Ti, V) intermetallics were studied using first-principles calculations. The energy barrier for dislocation formation in Al3Sc was found to be higher than that in Al3Ti and Al3V. The formation of anti-phase boundary (APB) in Al3V was energetically favored. Edge dislocation was easier to move than screw dislocation in Al3Sc, Al3Ti, and Al3V. Al3Sc and Al3Ti may have a better strengthening effect in aluminum alloys compared to Al3V. Al3Ti exhibited less temperature dependence in thermodynamic properties and can be a better candidate for improving the heat resistance of aluminum alloys.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Physics, Applied
Shaofeng Wang
Summary: An improved theoretical self-consistent method is presented for studying the heterojunction, which treats the period in the gamma-energy function as a parameter to be determined in a self-consistent way. Applied to the AlN/BN heterojunction, the period determined from the minimum-energy principle is found to be very close to the previously given value.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Xin Mei, Yuzhao Xu, Yaxin Zhu, Lv Zhao, Zhenhuan Li, Minsheng Huang
Summary: The interaction between edge extended dislocation and microvoids in high entropy alloys was investigated using atomistic simulations. The simulation results demonstrated that the high entropy effect, caused by multiple principal elements, significantly influenced the physical parameters, dislocation properties, and critical resolved shear stress of the alloy.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Metallurgy & Metallurgical Engineering
Guo-Liang Shi, Kui Zhang, Xing-Gang Li, Yong-Jun Li, Ming-Long Ma, Jia-Wei Yuan, Hong-Ju Zhang
Summary: The study analyzed the influence of thermomechanical treatment T10 on the dislocation structure and precipitation behavior in magnesium alloys, and found that T10 treatment can significantly enhance the strengthening effect of magnesium alloys. This is achieved by forming high-density basal I-1 stacking faults and < c + a > dislocations as nucleation sites and fast diffusion channels for continuous precipitates in extension twins.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Article
Materials Science, Multidisciplinary
S. Zhao, B. Li, B. A. Remington, C. E. Wehrenberg, H. S. Park, E. N. Hahn, M. A. Meyers
Summary: Shock compression subjects materials to high pressure and shear stresses, leading to temperature increase and mechanisms of plastic deformation, eventually causing amorphization. Covalently bonded materials face greater difficulty in responding to this extreme environment of shock compression.
Article
Engineering, Mechanical
Tengwu He, Yanzhou Ji, Yuming Qi, Long-Qing Chen, Miaolin Feng
Summary: This study investigates the stress dependence of dislocation evolution processes in copper using an improved microscopic phase field model. Through systematic simulations, it is found that the dislocation evolution regimes are closely related to the applied stress, and can be distinguished by three important critical stresses.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Materials Science, Multidisciplinary
Xue-Chun Zhang, Shuo Cao, Lian-Ji Zhang, Rui Yang, Qing-Miao Hu
Summary: In this paper, the competition between the {110}(111), {112}(111), and {123}(111) slip systems in BCC metals is determined by calculating the unstable stacking fault energy (yus) and Peierls stress (up) of these systems. It is found that yus is proportional to oB thorn G thorn =a2=3, where B, G, and a are the bulk modulus, shear modulus, and lattice constant, respectively. The calculations predict that the {110}(111) slip is prioritized, and up indicates a decrease in dislocation mobility in the order of {110}(111), {112}(111), {123}(111) for most metals. Notably, yus and up are not monotonically related.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Nanoscience & Nanotechnology
Chengbin Wei, Yiping Lu, Xinghao Du, Jun Wang, Tongmin Wang
Summary: The high-entropy alloys Co29Cr29Fe29Ni12.5W0.5 prepared by vacuum induction melting and mechanical processing exhibited outstanding mechanical properties with a yield strength of 1.13 GPa and fracture elongation of 24.3% after annealing at 725 degrees C. The addition of W element and ultrafine grain structure were attributed to the excellent mechanical properties observed in the alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Multidisciplinary
K. Mikes, F. Bormann, O. Rokos, R. H. J. Peerlings
Summary: The text discusses two different modeling approaches for understanding local defects in engineering materials: fully-resolved discrete systems and homogenized continuum formulations with specific enrichments. A comparison is made in terms of theory, accuracy, and performance, demonstrating capabilities and limitations of both methods. While continuum models with embedded cohesive zones offer good performance to accuracy ratios, they might not capture unexpected complex mechanical behavior. The Quasicontinuum method, on the other hand, provides more flexibility and higher accuracy with a slightly higher computational cost.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Nanoscience & Nanotechnology
Chengbin Wei, Yiping Lu, Xinghao Du, Jun Wang, Tongmin Wang
Summary: Nonequiatomic Co29Cr29Fe29Ni12.5W0.5 high-entropy alloys exhibited outstanding mechanical properties after annealing at 725 degrees C, attributed to the addition of the W element and ultrafine grain structure. Dislocation slip, stacking faults, and nano-twins governed the deformation mechanism in the annealed alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Qiang Wang, Liangcai Zeng, Tengfei Gao, Hui Du, Xinwang Liu
Summary: The microstructure and room-temperature tensile deformation behavior of the cast CrFeCoNiAl0.7 high-entropy alloy were investigated, revealing excellent tensile properties and the mechanisms of dislocation gliding, dislocation walls formation, and stacking faults generation during deformation.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Jan Klett, Isabel B. F. Mattos, Hans J. Maier, Regis H. G. e Silva, Thomas Hassel
Summary: Underwater wet welding has become increasingly relevant for repair work on offshore structures, but it poses numerous challenges due to the risk of hydrogen-induced cracking, especially in high-strength steels. High hardness values and high levels of diffusible hydrogen in the weld metal are major factors contributing to this risk.
MATERIALS AND CORROSION-WERKSTOFFE UND KORROSION
(2021)
Article
Materials Science, Multidisciplinary
David Goerzen, Florian Patrick Schaefke, Bastian Blinn, Christian Klose, Hans Juergen Maier, Tilmann Beck
Summary: The research used cyclic indentation tests to determine local mechanical properties of extruded EN AW-6082 profiles, showing how these properties are influenced by extrusion ratios and subsequent heat treatment. Higher extrusion ratios led to increased hardness, with further enhancements observed after T6 heat treatment.
Article
Chemistry, Physical
Oliver Braetz, Jan Klett, Thomas Wolf, Knuth-Michael Henkel, Hans Juergen Maier, Thomas Hassel
Summary: Hydrogen-assisted cracking is a major challenge in underwater wet welding of high-strength steels. Induction heating can effectively reduce the diffusible hydrogen content in the weld metal.
Article
Chemistry, Physical
Susanne Elisabeth Thuerer, Kai Peters, Torsten Heidenblut, Norman Heimes, Julius Peddinghaus, Florian Nuernberger, Bernd-Arno Behrens, Hans Juergen Maier, Christian Klose
Summary: In this study, semi-finished products for the manufacture of hybrid bearing bushings were produced using co-extrusion of coaxially reinforced hollow profiles. The push-out tests showed the shear strengths of hybrid hollow profiles with different material combinations. The influence of force and form closure on the joint zone was determined through shear compression tests. Thin lamellae prepared with a Focused Ion Beam were used for microstructural analysis.
Article
Materials Science, Multidisciplinary
Manuel Rodriguez Diaz, Maik Szafarska, Rene Gustus, Kai Moehwald, Hans Juergen Maier
Summary: By using a mixture of monosilane and nitrogen as the atomising and environment gas, oxide-free coatings were achieved, leading to improved adhesive tensile strength of wire arc sprayed copper coatings and a significant reduction of coating porosity.
Article
Materials Science, Multidisciplinary
Lara Vivian Fricke, Gregory Gerstein, Andreas Kotzbauer, Bernd Breidenstein, Sebastian Barton, Hans Juergen Maier
Summary: During cryogenic cutting, high strain rates result in a decrease in the content of α'-martensite and the formation of a lath-like structure. However, no α'-martensite is present in specimens subjected to compression loading. Magnetic etching proves to be an effective method in verifying the transformation of α'-martensite.
Article
Materials Science, Multidisciplinary
Lukas Munk, Silvia Reschka, Hans Juergen Maier, Peter Wriggers, Stefan Loehnert
Summary: A sharp-interface model using the extended finite element method is proposed to simulate the gamma-gamma' phase transformation in nickel-based superalloys. Combining crystal plasticity and sharp-interface theory, this model provides a good alternative to approaches based on the Cahn-Hilliard equation, and accurately captures the behavior of the interface during the phase transformation.
Article
Materials Science, Multidisciplinary
Vincent Fabian Viebranz, Thomas Hassel, Hans Juergen Maier
Summary: In this study, an iron-based FeMnAlNi shape memory alloy was processed using tungsten inert gas wire and arc additive manufacturing. The structure was cooled after each weld to maintain a constant temperature-time path, resulting in an anisotropic microstructure with promising grain orientation for high transformation strains.
Article
Materials Science, Multidisciplinary
Sebastian Barton, Maximilian K-B Weiss, Hans Juergen Maier
Summary: A new method was introduced in this study to continuously determine the microstructural changes in nickel-based materials under high-temperature fatigue. The results showed that different loading parameters can affect the maximum chromium depletion and depletion depth, which in turn affect the magnetic properties of the material.
Article
Materials Science, Multidisciplinary
Manuel Rodriguez Diaz, Selina Raumel, Marc Christopher Wurz, Maik Szafarska, Rene Gustus, Kai Moehwald, Hans Juergen Maier
Summary: Conventional thermal spraying processes in air atmosphere result in oxidation, but this study successfully applied spraying materials with high oxygen affinity in an oxide-free environment created by silane-doped inert gases, showing potential for industrial applications.
Article
Chemistry, Physical
Jan Klett, Benedict Bongartz, Vincent Fabian Viebranz, David Kramer, Chentong Hao, Hans Juergen Maier, Thomas Hassel
Summary: This study explores the possibility of using thermal silane-doped argon plasma to reduce the oxide layer on aluminum in situ for high-quality brazing. The results show that silane-doped argon plasma can significantly reduce oxygen concentration and decrease the thickness of the artificial oxide layer.
Article
Crystallography
Seyed Vahid Sajadifar, Hans Juergen Maier, Thomas Niendorf, Guney Guven Yapici
Summary: The elevated-temperature deformation characteristics and microstructural evolution of a Ti-5V-5Mo-5Cr-4Al alloy were studied under solution-treatment conditions. The dominant softening mechanism was found to be dynamic recovery (DRV), with dynamic precipitation (DPN) occurring only at specific strain rates and temperatures. Void coalescence was observed with increasing deformation temperature and decreasing strain rate. These findings provide insights for the processing of this novel beta titanium alloy.
Article
Materials Science, Multidisciplinary
Timm Coors, Mohamad Yusuf Faqiri, Felix Saure, Christoph Kahra, Christoph Buedenbender, Julius Peddinghaus, Vannila Prasanthan, Florian Pape, Thomas Hassel, Sebastian Herbst, Florian Nuernberger, Hendrik Wester, Johanna Uhe, Bernd Breidenstein, Berend Denkena, Bernd-Arno Behrens, Gerhard Poll, Hans Juergen Maier
Summary: Additive manufacturing with multi-material design offers great possibilities for lightweight and function-integrated components. By carefully adjusting the welding process, hybrid steel-steel components with high fatigue strength can be produced. Using stainless powder material as cladding, the resulting components have a longer service life compared to traditional monolithic washers.
Article
Engineering, Electrical & Electronic
Markus Mlinaric, Hassen Jemaa, Thomas Hassel, Hans Juergen Maier
Summary: The present study analyzes the damage mechanisms that cause premature failure of sapphire water jet orifices using an experimental and finite element modeling approach. The research findings show that the main risk for orifices to fail prematurely is the impact of particles, rather than excessive assembly forces. The experimental data reveals that particles with a diameter of more than 10 μm are critical, and even smaller particles of 2 μm can cause damage to the orifice jewel. To prevent premature failure due to foreign particles, water filtration with a 2 μm mesh is recommended, and further research is needed to focus on the design of the interior cutting head.
Article
Materials Science, Multidisciplinary
Steffen Wackenrohr, Christof Johannes Jaime Torrent, Sebastian Herbst, Florian Nurnberger, Philipp Krooss, Christoph Ebbert, Markus Voigt, Guido Grundmeier, Thomas Niendorf, Hans Jurgen Maier
Summary: Pure iron is a biodegradable implant material with high biocompatibility, and the combination with additive manufacturing allows for flexible adjustment of microstructure to control corrosion and fatigue behavior. This study compares conventional hot-rolled pure iron with pure iron manufactured by electron beam melting, and investigates the differences in microstructure, corrosion behavior, and fatigue properties. The results show significant variations in the studied sample conditions, leading to different corrosion and fatigue responses.
NPJ MATERIALS DEGRADATION
(2022)