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SSRN 2024年

作者： Liu, Baiyu Liu, Liang Cao, Xuan Wang, Shuo Chen, Wen Zhang, Yue Wu, Fufa Shang, Jian Zhao, Rongda Qi, Jingang Department of Materials Science and Engineering Liaoning University of Technology Liaoning Jinzhou121001 China Department of Mechanical and Industrial Engineering University of Massachusetts AmherstMA01003 United States

High-entropy alloys (HEAs) with face-centered cubic crystal structure (FCC) usually have good ductility but relatively low strength. In this work, we propose a new strategy to address the insufficient strength of FCC structured HEAs. The strategy is carried out in two ways: (1) By reducing the stacking fault energy of alloy system to improve its work hardening ability;(2) By adjusting the content of alloying element to control the quantity of L12 phase and σ phase, thereby strengthening its matrix. Based on the above ideas, the non-equimolar Fe2CoNiVx HEAs were designed by adjusting the element content of the classic FeCoNiV HEA. The results show that Fe2CoNiV1.3 alloy has excellent work-hardening ability and strength, of which work hardening index is improved by 36%, the yield and fracture strength are increased by 12.6% and 40.8% compared to FeCoNiV HEA, respectively. Additionally, the Fe2CoNiV1.3 alloy also has the best strength-plasticity trade-off. Its yield strength, ultimate tensile strength and elongation are 315.5 MPa, 724.2 MPa and 33.9%, which is superior to the vast majority as-cast FCC structured HEAs. This study not only reduces the cost, improves the alloy’s strength and toughness, but also provides ideas for the composition design of new advanced HEAs. © 2024, The Authors. All rights reserved.

关键词： High-entropy alloys

An Ontology-based Knowledge Modeling towards Eco-Design for Additive Manufacturing

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Procedia CIRP 2024年 122卷 760-765页

作者： Yanan Wang Tao Peng Samyeon Kim Yi Xiong Yunlong Tang Renzhong Tang State Laboratory of Fluid Power Components and Mechatronic Systems School of Mechanical Engineering Zhejiang University Hangzhou 310058 China Department of Mechanical Engineering Jeonju University Jeonju-si Jeollabuk-do 55069 South Korea School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen 518055 China Mechanical and Aerospace Engineering Department Monash University Melbourne 3800 Australia Materials Science and Engineering Department Monash University Melbourne 3800 Australia Zhejiang Province Key Laboratory of Advanced Manufacturing Technology School of Mechanical Engineering Zhejiang University Hangzhou 310058 China

Owing to the unique technological merits of additive manufacturing (AM), design for AM, particularly eco-design for AM, has been gaining attention in improving the sustainable performance of AM-fabricated (AMed) parts. The main challenge in harvesting potential sustainability benefits is how to capture the impact of design on sustainable performance. Though several existing studies adopted quantitative evaluation on AM sustainability and investigated the relationships between design information and sustainability information of AMed part, the sustainability information is still unavailable in the design phase. This hardly guides eco-design for AM in practice. To support the increasing industrial applications of AM, this paper illustrates related knowledge, that is, material-process-structure-ecoProperty (MPSeP) relationships to connect design and sustainability information in eco-design for AM. An ontology-based method is proposed to model the MPSeP relationships of the AMed part in a structured way. An example of an AMed hydraulic valve body was used to demonstrate the MPSeP modeling process. It is discussed that how the constructed model effectively assists AM designers through providing eco-design recommendation, and enables design software tools to perform sustainability analysis towards eco-design for AM.

关键词： additive manufacturing eco-design for additive manufacturing ontology model sustainability

Core-shell metallic nanotube arrays for highly sensitive surface-enhanced Raman scattering (SERS) detection

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Journal of Vacuum science and Technology A: Vacuum, Surfaces and Films 2023年第6期41卷 063111-063111页

作者： Chu, Jinn P. Yeh, Yi-Jui Liu, Chih-Yu Yang, Yi-Xiang Altama, Alfreda Krisna Chang, Ting-Hao Chiang, Wei-Hung Yiu, Pakman Tung, Kuo-Lun Department of Materials Science and Engineering National Taiwan University of Science and Technology Taipei106335 Taiwan Department of Chemical Engineering National Taiwan University Taipei106216 Taiwan Department of Chemical Engineering National Taiwan University of Science and Technology Taipei106335 Taiwan Department of Materials Engineering Ming Chi University of Technology New Taipei City243303 Taiwan Department of Mechanical Engineering and Materials Science Yale University New HavenCT06511 United States

Here, we demonstrate the application of highly ordered, periodic Ag/Au core-shell triangle nanotube arrays as an ultrasensitive and low-cost surface-enhanced Raman scattering (SERS) substrate for the first time. The arrays of core-shell nanotube, with an outer diameter of 1.5 ?m, were fabricated using top-down wafer-scale lithography followed by sequential sputter deposition of Ag and Au. The SERS activity of various combinations of core-shell structures was evaluated. It was found that Ag-core nanotubes overlaid with the Au-shell resulted in the highest Raman intensity, where the enhancement factor for R6G as a probe molecule is determined to be 1.38 × 107. Meanwhile, the limit of detections for R6G and ketoprofen analytes was evaluated to be 10?10 and 10?6 M, respectively. Linear correlations between the SERS signal intensities and logarithmical scale of both analytes in different concentrations were also established, ranging 10?4 10?10 and 10?2 10?6M for R6G and ketoprofen, respectively. The Raman R6G peak intensity mapping suggests our metal nanotube arrays act as effective plasmonic hotspots and, thus, are useful for SERS sensing applications. © 2023 AVS science and Technology Society. All rights reserved.

关键词： Nanotubes

Durability of Highly Active PGM Catalyst MEA Tested Via Nitrogen and Air AST Cycling Under HDV Condition

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Durability of Highly Active PGM Catalyst MEA Tested Via Nitr...

24th Symposium on Polymer Electrolyte Fuel Cells and Water Electrolyzers, PEFC and WE 2024, held at the PRiME 2024 Meeting

作者： Zhu, Guangqi Zhang, Qi Yu, Haoran Cullen, David A. Jeon, Sungho Ortiz, Erika Stach, Eric A. Marina, Oana C. Li, Zheng-Hua Xie, Jian School of Mechanical Engineering Purdue University West LafayetteIN47906 United States Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak RidgeTN37831 United States Department of Materials Science & Engineering University of Pennsylvania PhiladelphiaPA19104 United States Earth and Environmental Sciences Division Los Alamos National Laboratory Los AlamosNM87545 United States

ISBN: (纸本)9781623326630

PEMFCs are widely considered as the most promising power sources, particularly for heavy-duty vehicles (HDVs). Unfortunately, the degradation of MEAs under HDV condition remains insufficiently studied. In this work, we systematically investigated two MEAs with catalysts of Pt nanoparticles (NPs) supported over high surface area carbon black. These MEAs were tested for durability under HDV condition in nitrogen using a DOE AST protocol for 180,000 cycles, which is equivalent to 30,000 hours or 1 million miles of operation. The commercial Catalyst MEA also underwent 6,000 AST cycles in air under M2FCT condition. We comprehensively investigated the degradation of catalysts. Our results indicate that both MEAs undergo continuous performance degradation in H2/air and H2/O2 during the AST cycling in nitrogen, where analysis employing scanning transmission electron microscopy (STEM) and inductively coupled plasma mass spectrometry (ICP-MS) reveal significant degradation behavior for Pt catalysts. The MEA exhibits more significant degradation, especially within mass transfer region, during the AST process in air. This study describes the long-term degradation behavior and mechanism with AST cycling in nitrogen or air governing highly efficient and durable PGM-catalyst MEA design under HDV conditions. © The Electrochemical Society.

关键词： Inductively coupled plasma mass spectrometry

Analysis of Forming-Ageing Route on Post Incremental Forming Microstructure, mechanical Properties and Residual Stresses of an Al-Cu Alloy

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SSRN 2024年

作者： Hussain, Ghulam Khan, Shaukat Riaz, Asim Ahmed Alkahtani, Mohammed Wu, Hongyan Mechanical Engineering Department University of Bahrain Isa Town32038 Bahrain Faculty of Mechanical Engineering GIK Institute of Engineering Sciences and Technology Topi23460 Pakistan Mechanical Engineering Department UET Peshawar Pakistan Department of Industrial Engineering College of Engineering King Saud University P.O.Box 800 Riyadh11421 Saudi Arabia School of Chemistry and Materials Science Nanjing University of Information Science and Technology Nanjing China

The AA2219 is an Al-Cu alloy with widespread engineering applications. The sheet parts of this alloy are produced by metal forming and are subjected to age hardening (e.g., T6 temper) for strengthening. The cold work in metal forming affects the ageing behavior of alloy and hence the resulting mechanical properties. In this research, a novel forming technique namely Incremental Forming with three different forming-ageing routes is employed to produce age-hardened AA2219 parts. The resulting microstructure evolution, mechanical properties and residual stresses are examined. The results reveal that forming imposed cold work (35% plastic strain) enhances the sheet strength and hardness to a certain extent, and which can be further enhanced by opting an optimum forming-ageing route. Similarly, the residual stresses also show sensitivity to the forming-ageing route opted. Based upon extensive analysis of the experimental results, it is concluded that the [O-IF-ST-T6] route is the most appropriate route for producing age-hardened parts with high strength, hardness and ductility and low residual stresses (where O, IF, ST and T6 represent parent, incremental forming, solution treatment and T6 ageing, respectively). This route is found to offer a gain of 238% in the tensile yield strength, 151% in the ultimate tensile strength and 200% in the hardness. Further, from several correlations drawn between microstructural quantities and mechanical properties, it is identified that precipitation strengthening is the main strengthening mechanism for the results obtained. © 2024, The Authors. All rights reserved.

关键词： Tensile strength

Embedded Ni/Nio Heterojunction In MoO3-x Nanorods Toward Reinforced Interfacial Polarization for Electromagnetic Wave Absorption

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SSRN 2024年

作者： Zhang, Zhuqing Wang, Baojun Wang, Guohu Niu, Hongen Xu, Yangyang School of Mechanical and Electrical Engineering Zhengzhou University of Industrial Technology Zhengzhou451100 China School of Materials Science and Engineering Anhui University Hefei23060l China

Heterogeneous structures have been recognized as the promising strategy to reinforce dielectric polarization response through constructing intimate heterogeneous interfaces. However, the preparation of controllable and homogeneously distributed heterojunctions remains a great challenge. Herein, we proposed a moderate reduction strategy to in situ synthesize NiO/Ni heterojunction compactly embedded in MoO3-x nanorods by partially controlling phase evolution of NiO to Ni under the H2/Ar atmospheres. Profiting from the embedded NiO/Ni heterogeneous interfaces induced electron migration and redistribution at NiO/Ni interfaces, the NiO/Ni/MoO3-x absorbers show strengthened interfacial polarization relaxation response. Additionally, abundant O-vacancies as polarization centers form independent electric dipole pair, which favors to boost dipole polarization under alternating electromagnetic filed. The homogeneously distributed magnetic Ni species construct magnetic coupling network and generate ferromagnetic resonance and eddy current loss. Consequently, the prepared absorbers display superior electromagnetic wave absorption performances with a minimum reflection loss value of -64.18 dB at the thickness of 4.0 mm and maximum absorption bandwidth up to 6.6 GHz. The obtained absorption properties almost surpass most of the reported composites with embedded heterogeneous structures. This work provides a novel strategy for the preparation of heterogeneous interfaces and deep insight into the attenuation mechanisms of absorbers. © 2024, The Authors. All rights reserved.

关键词： Nickel oxide

A crystal plasticity phenomenological model to capture the non-linear shear response of carbon fibre reinforced composites

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International Journal of Lightweight materials and Manufacture 2021年第1期4卷 99-109页

作者： Tan, Wei Falzon, Brian G. School of Engineering and Materials Science Queen Mary University London London United Kingdom Advanced Composites Research Group School of Mechanical and Aerospace Engineering Queen's University Belfast Belfast United Kingdom

A hardening response is often observed for shear-dominated large deformation of Carbon Fibre Reinforced Plastics (CFRP). This non-linear response is often modelled by fitting a strain hardening law against experimental stress-strain curves. Inspired by a crystal plasticity framework, a phenomenological model is developed to capture matrix shearing and fibre rotation of CFRP under finite strain. This phenomenological model is first verified by simple shear and transverse compression tests, followed by comprehensive validations against measured stress-strain responses of unidirectional (UD) and cross-ply composite laminates subjected to quasi-static loading. The analytical and finite element predictions of CFRP lamina under simple shear loading confirm that the initial yielding is governed by the shear yield strength of the matrix, while the hardening behaviour is dependent on the modulus and rotation of the carbon fibres. This model accurately predicts the non-linear behaviour of CFRP under off-axis loading without the need of an empirical curve-fitted strain hardening law. © 2020 The Authors

关键词： Polymer matrix composites

Examining the Usability and Security Features of Smart Farm IoT Systems

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Examining the Usability and Security Features of Smart Farm ...

2023 International Conference on Power Energy, Environment and Intelligent Control, PEEIC 2023

作者： Khawale, Vijay R. Fidvi, Huzaifa A. Shamout, Mohamed Dawood Nama, Gigih Forda Anute, Nilesh Limbore, Nilesh Yeshwantrao Chavan College of Engineering Mechanical Department Nagpur India Anjuman College of Engineering and Technology Mechanical Engineering Sadar Maharashtra Nagpur India College of Business Administration University of Sharjah Department of Management Sharjah United Arab Emirates University of Lampung Department of Informatics Doctoral Program of Environtmental Science Bandar Lampung Indonesia ASM's Institute of Business Management and Research Pune India Sharadchandra Pawar Institute of Management and Research Pune India

ISBN: (纸本)9798350357769

Using the net of factors (IoT) technology has led to a resurgence in improving intelligent farms. The capacity to music and reveal crops, animals, and different farm activities has advanced the performance of farming operations. Clever farms enjoy the blessings of connectivity, allowing farmers to be more informed and higher prepared for any ability issues. This increased connectivity has also opened the door for new security problems. This paper looks at intelligent farm IoT structures' usability and safety features. The paper investigates the overall protection levels of the systems and the various security measures that may be implemented as an excellent way to discover and guard in opposition to ability threats. It also evaluates the usability of the structures and assesses the extent of convenience it offers for agriculture employees. The paper also evaluates the present-day enterprise tendencies in IoT protection, value, and potential future trends. Ultimately, the paper gives insights into modern and future security and usability measures that may be taken to ensure the protection and effectiveness of clever farm IoT systems. The paper examines the usability and protection capabilities of innovative Farm Internet of Things (IoT) structures, which provide farmers with the potential to monitor, manipulate, and control various farm elements remotely. Usability functions consisting of user interfaces, device connectivity, and communication protocols are analyzed to evaluate how user-friendly the device is. Additionally, safety functions consisting of authentication, authorization, encryption, and getting entry to manage are tested to decide how the gadget can defend the statistics and assets of the farm. Moreover, this paper touches upon the contemporary and destiny-demanding situations related to those structures, including scalability, cost, and privacy. ultimately, the paper concludes with a comprehensive assessment of the usability and security functions and

关键词： ability implemented increased intelligent opposition

Pi-Pda@Psf@To Composite Coating Toward Multifunctional Development: Self-Lubrication, Self-Healing, and Heat-Resistance

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SSRN 2024年

作者： Si, Chengyi Xiong, Liangliang Fan, Xiaoqiang Zhang, Yawen Li, Le Liu, Hongyu Zhu, Minhao School of Materials Science and Engineering Southwest Jiaotong University Chengdu610031 China Tribology Research Institute School of Mechanical Engineering Southwest Jiaotong University Chengdu610031 China

To facilitate versatile application of polyimide (PI) under harsh conditions, the PI-PDA@PSF@TO coating was successfully obtained. Upon coating damage, PI-PDA@PSF@TO persists in the salt environment for 8 days. Compared to PI, the wear rate of the PI-PDA@PSF@TO is reduced by 42.7%. After thermal oxidation, the friction coefficient decreases from 0.501 to 0.377 and the wear rate decreases from 6.33×10−7 mm3N−1m−1 to 3.31×10−7 mm3N−1m−1. The improvement contributes to two factors: (I) The PDA@PSF@TO microcapsules, developed by combining polysulfone (PSF) and polydopamine (PDA), achieves the stable storage of tung oil (TO) in PI. (II) The release of TO forms protective layers, which compensate for defects and provide excellent tribological properties, thereby demonstrating self-healing and self-lubricating capabilities of coatings. © 2024, The Authors. All rights reserved.

关键词： Polyimides

An EMG-based Spatio-spectro-temporal Index for Muscle Fatigue Quantification

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An EMG-based Spatio-spectro-temporal Index for Muscle Fatigu...

IEEE International Workshop on Robot and Human Communication (ROMAN)

作者： N.P. Dasanayake R.A.R.C. Gopura R.K.P.S. Ranaweera T.D. Lalitharatne Department of Mechanical Engineering Faculty of Engineering University of Moratuwa Moratuwa Sri Lanka School of Engineering and Materials Science Queen Mary University of London London UK

This study introduces a new EMG-based muscle fatigue index that combines EMG signal features in spatial, temporal, and spectral domains. This index incorporates a novel spatial EMG feature: Eigen Ratio Based Fatigue Index (ERFI) that can capture the variations in the active motor unit distribution during dynamic muscle fatiguing exercises. The new fatigue index maps the ERFI, a wavelet-based feature, a spectral feature, and an amplitude-based feature to the reduction in maximum voluntary contraction, which is considered the direct measure of muscle fatigue. The mapping function was implemented as a Multi-layer Perceptron (MLP). To evaluate the fatigue index, several fatigue tests under various speed and load conditions were conducted on four subjects. ERFI showed a significant variation (p < 0.01) over time for more than 85 % of the tests. Several MLP input configurations to predict muscle fatigue were compared in this study based on various combinations of EMG features. An input configuration that used the novel spatial EMG feature among five other features performed the best and was able to predict muscle fatigue with a mean coefficient of determination over 65 %. It was also noticed that ERFI’s relationship with muscle fatigue is less dependent on the load and speed of the cyclic exercise when compared with other EMG features that were proposed in previous studies. Thus it can be considered a better alternative to use in EMG-based control of active prosthetic and orthotic devices to compensate for the effect of muscle fatigue.

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