Article
Materials Science, Multidisciplinary
Libo Fu, Chengpeng Yang, Yan Lu, Jiao Teng, Deli Kong, Yizhong Guo, Ze Zhang, Lihua Wang, Xiaodong Han
Summary: The study found that there are three different types of detwinning mechanisms in nanocrystalline AuAg alloys, which are caused by grain boundary migration, combined layer-by-layer thinning and incoherent twin boundary migration, and collective motion of partial dislocations in an array.
SCIENCE CHINA-MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Anuj Bisht, Michael Kalina, Eylul Suadiye, Gunther Richter, Eugen Rabkin
Summary: In this study, nanoscale bimetallic strips were fabricated by one-sided coating with Pd, leading to slight bending of the strips. The temperature-induced shape changes of the Au-Pd strips were investigated via in-situ thermal actuation. The results demonstrate that single crystalline metallic nanowhiskers with controlled curvature, chemical composition, and thermal behavior can be produced using interface engineering and chemical interdiffusion.
Article
Materials Science, Multidisciplinary
Wenqian Wu, Mingyu Gong, Bingqiang Wei, Amit Misra, Jian Wang
Summary: Al-Si cast alloys composed of alpha-Al and Al-Si eutectic often do not show significant improvement in mechanical properties due to Si flakes. The weak strengthening effect of Si flakes may be attributed to the low shear resistance and easy interaction of dislocations with Al-Si interfaces, leading to a decrease in the repulsive force on approaching dislocations and weakening the strengthening effect of Si flakes.
Article
Materials Science, Multidisciplinary
Hyojung Kim, Nithin Mathew, Darby J. Luscher, Abigail Hunter
Summary: Body-Centered Cubic (BCC) metals exhibit anomalous mechanical properties attributed to asymmetric behavior of screw dislocations, resulting in deviation of Critical Resolved Shear Stress (CRSS) from the Schmid law. By utilizing Phase Field Dislocation Dynamics (PFDD) modeling, it is possible to simulate and understand the non-Schmid behavior by incorporating representative dislocation properties and different energy terms in the model. The predicted CRSS using PFDD modeling shows excellent agreement with Molecular Statics (MS) predictions.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Chemistry, Multidisciplinary
Valeriy Dudko, Diana Yuzbekova, Rustam Kaibyshev, Chiara Soffritti
Summary: Strengthening mechanisms were examined in a Fe-0.43C-1.60Si-0.01Mn-1.1Cr-0.95Mo-0.08V-0.05Nb steel, where dislocation strengthening was major in the tempered condition and dispersion strengthening was major in the tempformed condition. The high values of dislocation strengthening in the tempered condition were attributed to dislocations at lath boundaries, while a high density of free dislocations provided similar strengthening in the tempformed condition. Warm rolling after tempering led to increased dispersion strengthening due to alignment of intercrystalline boundaries.
APPLIED SCIENCES-BASEL
(2023)
Article
Materials Science, Multidisciplinary
Qianqian Fu, Bing Li, Hongwang Fu, Minqiang Gao, Changfeng Wang, Ying Fu, Renguo Guan
Summary: This study systematically investigates the cryogenic and room temperature drawing behaviors of Cu-Te alloy. It finds that the liquid nitrogen temperature drawn Cu-Te alloy has higher yield strength and ultimate tensile strength, and promotes the formation of deformation twinning and shear bands.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Multidisciplinary Sciences
Xuexi Yan, Yixiao Jiang, Qianqian Jin, Tingting Yao, Weizhen Wang, Ang Tao, Chunyang Gao, Xiang Li, Chunlin Chen, Hengqiang Ye, Xiu-Liang Ma
Summary: By combining transmission electron microscopy, first-principles calculations, and cathodoluminescence spectroscopy, we demonstrate unexpected strong interfacial interactions at the incoherent AlN/Al2O3 (0001) interface with a large mismatch, which result in the formation of misfit dislocation networks and stacking faults rarely observed at other incoherent interfaces. The strong interfacial interactions significantly tailor the interfacial atomic structure and electronic properties, leading to a reduced band gap and strong interfacial ultraviolet light emission. These findings suggest the potential of incoherent interfaces in developing novel heterojunction materials and devices.
NATURE COMMUNICATIONS
(2023)
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
Md Shahrier Hasan, Gregory Berkeley, Kyrel Polifrone, Wenwu Xu
Summary: Metal matrix nanocomposites (MMNCs) behave differently from micro-composites due to the high density of matrix/reinforcer interfaces resulting from nanoscale reinforcements. This study conducted molecular dynamics simulations to investigate the deformation mechanisms and defects evolution in an aluminum-silicon carbide nanocomposite. It was found that the nanoparticle volume fraction significantly affected dislocation-based deformation, while particle size had a greater impact on failure-based deformation.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Zhao Cheng, Linfeng Bu, Yin Zhang, HengAn Wu, Ting Zhu, Huajian Gao, Lei Lu
Summary: This study investigates the extra strength of gradient nanotwinned (GNT) Cu compared to uniform nanotwin counterparts. The research finds that the extra strength of GNT Cu is mainly due to the extra back stress resulting from the nanotwin thickness gradient. The structural gradient in GNT Cu leads to an increasing plastic strain gradient, which raises the extra back stress. The combined experimental and modeling results reveal a fundamental connection between the gradient structure and extra strength in GNT Cu through the mechanistic linkages of plastic strain gradient, heterogeneous dislocation structure, microscale internal stress, and extra back stress.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Nanoscience & Nanotechnology
Jiaxiang Wang, Xin Wang, Kehang Yu, Timothy J. Rupert, Subhash Mahajan, Enrique J. Lavernia, Julie M. Schoenung, Irene J. Beyerlein
Summary: The study investigates the effect of Y concentration on slip and twinning mechanisms in binary Mg-Y alloys. Increasing Y concentration reduces the intensities of the initial and deformation textures, as well as plastic anisotropy, tension-compression asymmetry, and twinning. The model suggests that increased Y concentration increases the critical resolved shear stress for basal slip and reduces plastic anisotropy, leading to enhanced non-basal activity in Mg-Y alloys.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Zailin Yang, Xiaoyang Ding, Yong Yang, Minghe Li, Shihao Cao
Summary: This study analyzes the effects of nanotwinned structure gradient on the mechanical behavior of gradient nanotwinned metals using molecular dynamics method, and establishes a quantitative phenomenological plastic flow stress model. It provides guidance for the structural design of gradient nanotwinned metals.
FRONTIERS IN MATERIALS
(2022)
Article
Chemistry, Physical
G. Azuara-Tuexi, J. A. Mendez-Cabanas, E. Munoz-Sandoval, R. A. Guirado-Lopez
Summary: This study presents a combined experimental and theoretical analysis of the degradation of nitrogen-doped multi-walled carbon nanotubes by human myeloperoxidase in vitro. The degradation process leads to the removal of smaller diameter CNTs and the formation of highly deformed NMWCNTs decorated with NaCl nanoparticles. Density functional theory calculations reveal the reactivity of carbon walls around nitrogen-doped sites, leading to the presence of hypochlorite species and physisorbed HClO molecules.
Article
Nanoscience & Nanotechnology
Qian He, Shuhei Yoshida, Nobuhiro Tsuji
Summary: This study reports the characteristic strengthening mechanisms of HfNbTaTi, HfNbTiZr, HfNbTi, HfTaTi, and NbTiZr equi-atomic refractory medium entropy alloys (RMEAs). The alloys were processed to obtain microstructures with varying grain sizes and their mechanical properties were evaluated. The low elastic modulus of the RMEAs was found to be the reason for their small slopes of the Hall-Petch relationships and weak grain refinement strengthening. Moreover, the high friction stresses of the RMEAs were attributed to the interaction between severe lattice distortion and elastic field of edge dislocations.
SCRIPTA MATERIALIA
(2023)
Review
Engineering, Mechanical
Nian-Pu Xue, Qiong Wu, Yu Zhang, Bian-Hong Li, Yi-Du Zhang, Shuai Yang, Yu Zhu, Jian Guo, Han-Jun Gao
Summary: In this paper, the recent progress of four typical surface strengthening methods (MSP, USP, LSP, and BSM) is analyzed, including the basic theory and measurement methods of reflectivity (RS). The reaction mechanisms, influencing factors, strengthening effects, and fatigue improvement of these methods are explained, and various research methods and optimization strategies are summarized.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Metallurgy & Metallurgical Engineering
Lara V. Fricke, Hai Nam Nguyen, Bernd Breidenstein, David Zaremba, Hans Juergen Maier
Summary: This study successfully created a hardened martensitic subsurface layer during machining process through cryogenic, external turning method. Eddy current testing and analysis of higher harmonics were used to detect the ferromagnetic, martensitic phase in the parent austenite, and a good correlation was found between the amplitude of the signals measured and the martensite content. Eddy current testing is considered as a suitable real-time, nondestructive testing method for generating a tailored, deformation-induced martensitic subsurface layer during external turning.
STEEL RESEARCH INTERNATIONAL
(2021)
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)
Article
Engineering, Manufacturing
Andreas Hetzel, Robert Schulte, Manfred Vogel, Michael Lechner, Hans-Bernward Besserer, Hans Juergen Maier, Christopher Sauer, Benjamin Schleich, Sandro Wartzack, Marion Merklein
Summary: The article introduces the innovative process class of sheet-bulk metal forming and different approaches to manufacturing part geometries, analyzing the mechanical and geometrical properties of the parts. By using experimental and numerical data, a self-learning engineering workbench was employed to generate the desired CAD model and derive design guidelines based on the properties and fatigue behavior investigated.
JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING
(2021)
