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Establishing a Novel Process Route for Additive Manufacturing of NiCu-Based Alloy 400 – an Alignment of Gas Atomization, Laser Powder Bed Fusion and design of Experiments

SSRN

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SSRN 2023年

作者： Roth, Jan-Philipp Šulák, Ivo Kruml, Tomáš Polkowski, Wojciech Dudziak, Tomasz Böhlke, Peter Krupp, Ulrich Jahns, Katrin Laboratory for Materials Design and Structural Integrity Faculty of Engineering and Computer Science Osnabrück University of Applied Sciences Albrechtstraße 30 Osnabrück49076 Germany Institute of Physics of Materials Czech Academy of Sciences Žižkova 513/22 Brno616 00 Czech Republic Krakow Institute of Technology Lukasiewicz Research Network Ulica Zakopiańska 73 Kraków30-418 Poland KME Germany GmbH Klosterstraße 29 Osnabrück49074 Germany Steel Institute IEHK RWTH Aachen University Intzestraße 1 Aachen52072 Germany

Alloy 400 is a corrosion-resistant, NiCu-based material which is used in numerous industrial applications, especially in marine environments and the high-temperature chemical industry. As conventional manufacturing limits geometrical complexity, additive manufacturing (AM) of the present alloy system promises great potential. For this purpose, a robust process chain, consisting of powder production via gas atomization and a design of Experiments (DoE) approach for Laser Powder Bed Fusion (LPBF), was developed. With a narrow particle size distribution, powders were found to be spherical, flowable, consistent in chemical composition and hence, generally applicable to the LPBF process. Copper segregations at grain boundaries were clearly detected in powders. Still, for printed parts, only low-intensity micro segregations at cell walls were discovered, being correlated with the iterative thermal stress applied to solidified melt-pool-near grains during layer-by-layer manufacturing. For production of nearly defect-free LPBF structures, DoE suggested a single optimum parameter set instead of a broad energy density range. The latter key figure was found to be misleading in terms of part densities, making it an outdated tool in modern, software-based process parameter optimization. On the microscale, printed parts showed an orientation of melt pools along the build direction with a slight crystallographic [101] texture. Micro dendritic structures were detected on the nanoscale being intersected by a high number of dislocations. Residual porosity was reduced by application of hot isostatic pressing (HIP) while accepting a decrease in hardness. A vertical orientation of tensile test specimens with respect to the build platform resulted in low strength and high elongation when compared to a horizontal alignment. Checked against hot-extruded reference material, the LPBF variant performed better in terms of strength while lacking in ductility, being attributed to a finer grain s

关键词： Corrosion resistance

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Effects of Geometric Parameters on Performance of Rectangular Submerged Inlet for Aircraft

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Transactions of Nanjing University of Aeronautics and Astronautics 2021年第6期38卷 984-992页

作者： LIU Chao PEI Houju CHEN Changdong XU Wenbing YANG Kaijie Environment Control and Oxygen System Department Shanghai Aircraft Design and Research InstituteShanghai 201210P.R.China AVIC Nanjing Servo Control System Corporation Nanjing 210016P.R.China College of Energy&Power Engineering Jiangsu University of Science and TechnologyZhenjiang 212003P.R.China Key Laboratory of Aircraft Environment Control and Life Support MIITNanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China

To improve the comfortability and safety of aircraft,the demand of rectangular submerged inlets(RSIs)with low resistance is proposed to increase the inlet flow rate of ram air. A theoretical model is built to numerically analyze the effects of geometric parameters on the inlet mass flow rate of RSIs. The geometric parameters in question here encompass the aspect ratio of 2—4,the ramp angle of 6°—7°,the characteristic parameter of the throat of 0.20 —0.30,the ramp length of 939—1 337 mm,and the cone angle of 0° —3°. Simulation results demonstrate that the mass flow rate(MFR)is positively correlated with the aspect ratio,ramp angle,ramp length,and cone angle,and negatively correlated with characteristic parameter of the throat. Within the range of the geometric parameters considered,the RSI with the aspect ratio of 3,the ramp angle of 6°,the characteristic parameter of the throat of 0.20,the ramp length of 1 337 mm,and the cone angle of 3° obtains the largest MFR value of about 2.251 kg/s.

关键词： ram air system rectangular submerged inlet geometric parameter mass flow rate(MFR)

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A priori procedure to establish spinodal decomposition in alloys

arXiv

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arXiv 2023年

作者： Divilov, Simon Eckert, Hagen Toher, Cormac Friedrich, Rico Zettel, Adam C. Brenner, Donald W. Fahrenholtz, William G. Wolfe, Douglas E. Zurek, Eva Maria, Jon-Paul Hotz, Nico Campilongo, Xiomara Curtarolo, Stefano Department of Mechanical Engineering and Materials Science Duke University DurhamNC27708 United States Center for Autonomous Materials Design Duke University DurhamNC27708 United States Department of Materials Science and Engineering Department of Chemistry and Biochemistry University of Texas at Dallas RichardsonTX75080 United States Institute of Ion Beam Physics and Materials Research Helmholtz-Zentrum Dresden-Rossendorf Dresden01328 Germany Theoretische Chemie Technische Universität Dresden Dresden01062 Germany Department of Materials Science and Engineering North Carolina State University RaleighNC27695 United States Department of Materials Science and Engineering Missouri University of Science and Technology RollaMO65409 United States Applied Research Laboratory The Pennsylvania State University University ParkPA16802 United States Department of Chemistry State University of New York at Buffalo BuffaloNY14260 United States Department of Materials Science and Engineering The Pennsylvania State University University ParkPA16802 United States

Spinodal decomposition can improve a number of essential properties in materials, especially hardness. Yet, the theoretical prediction of the onset of this phenomenon (e.g., temperature) and its microstructure (e.g., wavelength) often requires input parameters coming from costly and time-consuming experimental efforts, hindering rational materials optimization. Here, we present a procedure where such parameters are not derived from experiments. First, we calculate the spinodal temperature by modeling nucleation in the solid solution while approaching the spinode boundary. Then, we compute the spinodal wavelength self-consistently using a few reasonable approximations. Our results show remarkable agreement with experiments and, for NiRh, the calculated yield strength due to spinodal microstructures surpasses even those of Ni-based superalloys. We believe that this procedure will accelerate the exploration of the complex materials experiencing spinodal decomposition, critical for their macroscopic properties. © 2023, CC BY.

关键词： Spinodal decomposition

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Prediction of monolayered ferromagnetic CrMnI6 as an intrinsic high-temperature quantum anomalous Hall system

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Physical Review B 2020年第11期102卷 115413-115413页

作者： Huisheng Zhang Wenjia Yang Ping Cui Xiaohong Xu Zhenyu Zhang Key Laboratory of Magnetic Molecules and Magnetic Information Materials of the Ministry of Education and Research Institute of Materials Science Shanxi Normal University Linfen 041004 China International Center for Quantum Design of Functional Materials (ICQD) Hefei National Laboratory for Physical Sciences at Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of China Hefei Anhui 230026 China Key Laboratory of Strongly-Coupled Quantum Matter Physics Chinese Academy of Sciences School of Physical Sciences University of Science and Technology of China Hefei Anhui 230026 China

Quantized Hall conductance without an external magnetic field, known as the quantum anomalous Hall effect (QAHE), may have important applications in dissipationless spintronics, yet to date, it has only been realized in magnetically doped topological insulators and at very low temperatures. Here we design a physically realistic system for realizing QAHE by expanding the recently discovered two-dimensional ferromagnetic insulators as a new class of candidate materials. Based on first-principles calculations, we predict that a CrMnI6 monolayer is energetically stable and can be readily exfoliated. This system is further shown to be a ferromagnetic insulator, with a transition temperature of ∼87K, higher than that of CrI3. Most strikingly, such a monolayer is characterized as an intrinsic QAHE system with a high Chern number of C = 2, and the underlying mechanism for the nontrivial topology is attributed to the two inequivalent subset sites of the Cr and Mn atoms. The present study thus provides an ideal platform for realizing high-temperature QAHE beyond the prevailing materials class of magnetically doped topological insulators.

关键词： First-principles calculations Topological materials 2-dimensional systems Ferromagnets Density functional theory Wannier function methods k dot p method

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A New Class of NIR-II Gold Nanocluster-Based Protein Biolabels for In Vivo Tumor-Targeted Imaging

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Angewandte Chemie (International ed. in English) 2021年第3期60卷 1306-1312页

作者： Xiaorong Song Wei Zhu Xiaoguang Ge Renfu Li Shihua Li Xian Chen Jibin Song Jianping Xie Xueyuan Chen Huanghao Yang MOE Key Laboratory for Analytical Science of Food Safety and Biology & State Key Laboratory of Photocatalysis on Energy and Environment College of Chemistry Fuzhou University Fuzhou Fujian 350116 China. Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou Fujian 350108 China. CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Key Laboratory of Nanomaterials Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences Fuzhou Fujian 350002 China. Department of Chemical and Biomolecular Engineering National University of Singapore 4 Engineering Drive 4 Singapore 117585 Singapore. Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City Fuzhou Fujian 350207 China.

The design of bright NIR-II luminescent nanomaterials that enable efficient labelling of proteins without disturbing their physiological properties in vivo is challenging. We developed an efficient strategy to synthesize bright NIR-II gold nanoclusters (Au NCs) protected by biocompatible cyclodextrin (CD). Leveraging the ultrasmall size of Au NCs (<2 nm) and strong macrocycle-based host-guest chemistry, the as-synthesized CD-Au NCs can readily label proteins/antibodies. Moreover, the labelled proteins/antibodies enable highly efficient in vivo tracking during blood circulation, without disturbing their biodistribution and tumor targeting ability, thus leading to a sensitive tumor-targeted imaging. CD-Au NCs are stable in the harsh biological environment and show good biocompatibility and high renal clearance efficiency. Therefore, the NIR-II biolabels developed in this study provide a promising platform to monitor the physiological behavior of biomolecules in living organisms.

关键词： NIR-II imaging cyclodextrin gold nanoclusters protein labelling tumor imaging

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Improved Modular Convolution Neural Network for Human Pose Estimation 12th

Improved Modular Convolution Neural Network for Human Pose E...

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12th International Conference on e-Learning and Games, Edutainment 2018

作者： Zhang, Zhengxuan Dong, Jing Zhou, Dongsheng Fang, Xiaoyong Wei, Xiaopeng Key Laboratory of Advanced Design and Intelligent Computing Dalian University Ministry of Education Dalian116622 China School of Computer Science and Technology Dalian University of Technology Dalian1160243 China Research Institute of Human Factors and Safety Engineering Hunan Institute of Technology HengyangHunan Province421002 China

ISBN: (纸本)9783030237110

Human pose estimation in image is an important branch of computer vision and graphics research. In this paper, an improved modular convolution neural network is proposed to solve the problem of human pose estimation in static 2D images. A cascaded three-stage full convolutional network (FCN) can learn the non-linear mapping from image feature space to human pose space in an end-to-end way. In order to improve the accuracy of predicting joints, the method of multi-feature source fusion is adopted to improve the estimation process of the human body posture. The first two stages of the network focus on learning local image features and joints neighborhood pixel features, and these features are merged in the third stage of the network. Finally, the coordinates of human joints are obtained by regression of the merged features. In our experiments, using the strict PCP criteria on the full body pose dataset LSP, the average prediction accuracy of our method is 79.3%. In addition, using the PCKh standard on the upper body pose dataset FLIC, our method achieves an average prediction accuracy of 93% without additional training. © 2019, Springer Nature Switzerland AG.

关键词： Forecasting

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Inverse design of higher-order photonic topological insulators

arXiv

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arXiv 2020年

作者： Chen, Yafeng Meng, Fei Kivshar, Yuri Jia, Baohua Huang, Xiaodong Key Laboratory of Advanced Technology for Vehicle Body Design & Manufacture Hunan University Changsha410082 China Faculty of Science Engineering and Technology Swinburne University of Technology HawthornVIC3122 Australia Nonlinear Physics Center Research School of Physics Australian National University CanberraACT2601 Australia

Topological photonics revolutionizes some of the traditional approaches to light propagation and manipulation, and it provides unprecedented means for developing novel photonic devices. Recently discovered higher-order topological phases go beyond the conventional bulk-edge correspondence for photonic crystals and introduce novel opportunities for topological protection. Here, we introduce an intelligent numerical approach for inverse design of higher-order photonic topological insulators with great flexibility for controlling both topological edge and topological corner states. In particular, we consider the second-order photonic topological insulator and design several structures supporting both edge and corner states at different frequencies. By carefully programming these structures, we suggest a novel approach for topological routing of the edge and corner states by changing the operational frequency. Our finding paves the way to integrated topological photonic devices with novel functionalities. Copyright © 2020, The Authors. All rights reserved.

关键词： Photonic crystals

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Calculation of adjoint-weighted reactor kinetics parameters in OpenMC

Calculation of adjoint-weighted reactor kinetics parameters ...

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2018 International Conference on Physics of reactors: reactor Physics Paving the Way Towards More Efficient Systems, PHYSOR 2018

作者： Peng, Xingjie Forget, Benoit Smith, Kord Science and Technology on Reactor System Design Technology Laboratory ChengduSichuan610000 China Nuclear Science and Engineering Department Massachusetts Institute of Technology 77 Massachusetts Ave. CambridgeMA02139 United States

ISBN: (纸本)9781713808510

Knowledge of adjoint-weighted kinetics parameters plays an importance role in analyzing the reactor safety and in describing the transient behavior of nuclear reactors during normal operation or accidents. In this work, the capability of calculating adjoint-weighted kinetic parameters, including the effective neutron generation time, the effective delayed neutron fraction, and the ratio of these two quantities was implemented in OpenMC code based on two different methods of interpreting the physical meaning of the adjoint weighting, namely, the iterated fission probability (IFP) method and the Contribution-Linked eigenvalue sensitivity/Uncertainty estimation via Tracklength importance CHaracterization (CLUTCH) method. The results of the implementation were benchmarked by comparison to MCNP5 calculations, Serpent2 calculations and experimental data in 10 critical configurations. © 2018 International Conference on Physics of reactors, PHYSOR 2018: reactor Physics Paving the Way Towards More Efficient Systems. All rights reserved.

关键词： Eigenvalues and eigenfunctions

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Experimental study on water-lubricated bearing material in deep sea space station 7th

Experimental study on water-lubricated bearing material in d...

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7th International Conference on Nanostructures, Nanomaterials and Nanoengineering, ICNNN 2018 and International Conference on Materials technology and Applications, ICMTA 2018

作者： Chunhui, Dai Xingsheng, Lao Yong, Liu Wei, Wang Science and Technology on Thermal Energy and Power Laboratory Wuhan 2rd Ship Design and Research Institute NO.19 Yangqiaohu Avenue Jiangxia District WuhanHubei China

ISBN: (纸本)9783035714302

With the deepening of marine development activities, human-related sea-related behavior has gradually moved from shallow sea to deep sea. In this paper, the deep sea environment of the thruster bearing of the deep sea space station is characterized by high pressure, high corrosion, large amount of microorganisms and sediment. The Modified UHMWPE is developed, and the friction under simulated seawater conditions is studied by using different proportions of samples. The experimental results show that the materials developed in this study have lower friction coefficient and better wear resistance than Thordon and Feroform materials, and are very suitable for deep sea environment. © 2019 Trans Tech Publications, Switzerland.

关键词： Wear resistance

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Traction adaptive motion planning and control at the limits of handling

arXiv

引用

arXiv 2020年

作者： Svensson, Lars Bujarbaruah, Monimoy Karsolia, Arpit Berger, Christian Törngren, Martin Department of Machine Design KTH Royal Institute of Technology Sweden Model Predictive Control Laboratory University of California Berkeley United States Department of Electrical Engineering Chalmers University of Technology Sweden Department of Computer Science and Engineering University of Gothenburg Sweden

In this paper, we address the problem of motion planning and control at the limits of handling, under locally varying traction conditions. We propose a novel solution method where traction variations over the prediction horizon are represented by time-varying tire force constraints, derived from a predictive friction estimate. A constrained finite time optimal control problem is solved in a receding horizon fashion, imposing these time-varying constraints. Furthermore, our method features an integrated sampling augmentation procedure that addresses the problems of infeasibility and sensitivity to local minima that arise at abrupt constraint alterations, e.g., due to sudden friction changes. We validate the proposed algorithm on a Volvo FH16 heavy-duty vehicle, in a range of critical scenarios. Experimental results indicate that traction adaptive motion planning and control improves the vehicle's capacity to avoid accidents, both when adapting to low local traction, by ensuring dynamic feasibility of the planned motion, and when adapting to high local traction, by realizing high traction utilization. Copyright © 2020, The Authors. All rights reserved.

关键词： Motion planning

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