检索结果-内蒙古大学图书馆

Atomic-scale friction between single-asperity contacts unveiled through in situ transmission electron microscopy (May, 10.1038/s41565-022-01126-z, 2022)

引用

NATURE NANOTECHNOLOGY 2022年第7期17卷 799-799页

作者： Wang, Xiang Liu, Zhenyu He, Yang Tan, Susheng Wang, Guofeng Mao, Scott X. Department of Mechanical Engineering and Materials Science University of Pittsburgh Pittsburgh PA USA Petersen Institute of Nanoscience and Engineering University of Pittsburgh Pittsburgh PA USA

Friction and wear are detrimental to functionality and reduce the service life of products with mechanical elements. Here, we unveil the atomic-scale friction of a single tungsten asperity in real time through a high-resolution transmission electron microscopy investigation of a nanocontact in countermotion, induced through a piezo actuator. Molecular dynamics simulations provide insights into the sliding pathway of interface atoms and the dynamic strain/stress evolution at the interface. We observe a discrete stick–slip behaviour and an asynchronous process for the accumulation and dissipation of the strain energy together with the non-uniform motion of interface atoms. Our methodology allows for studying in situ atomic-friction phenomena and provides insights into friction phenomena at the atomic scale.

关键词： Nanoscale materials Other nanotechnology

来源：评论

学校读者我要写书评

暂无评论

Models for predicting high-temperature hardness and wear rate responses of 6061-Al/boron carbide composite

Models for predicting high-temperature hardness and wear rat...

引用

2024 International Conference on science, engineering and Business for Driving Sustainable Development Goals, SEB4SDG 2024

作者： Adediran, Adeolu Adesoji Akinwande, Abayomi Adewale Ikumapayi, Omolayo Ajisegiri, Emmanuel Adeniran, Afolalu S. Landmark University Department of Mechanical Engineering Kwara State Omu-Aran Nigeria University of Johannesburg Department of Mechanical Engineering Science South Africa Federal University of Akure Department of Metallurgical and Materials Engineering Ondo State Nigeria Afe Babalola University Department of Mechanical Engineering Ekiti State Ado-Ekiti Nigeria

ISBN: (纸本)9798350358155

For the purpose of improving the high-temperature performance of Al 6061 in terms of hardness and wear, boron carbide (B4C) was added to Al 6061 at 5, 10, and 15 wt. % and the developed composite was tested for hardness and wear rate at temperatures of 250, 350, and 450 °C. This study focused on the experimental observation and modelling of the experimental data. It was observed that increase in temperature resulted in decrease in hardness with a corresponding increase in wear volume. Meanwhile, increasing dosage of the particle led to improvement in hardness and wear resistance. The result showed that optimum temperature exposure of the composite is ≤ 250 °C with dosage of B4C not > 10 wt. %. The developed predictive models were determined to possess good fitness with the experimental data, hence capable for predicting the hardness and wear rate. © 2024 IEEE.

关键词： Rockwell hardness

来源：评论

学校读者我要写书评

暂无评论

Porphyrin-Grafted Poly(ethylene terephthalate) as a Reusable and Highly Selective Colorimetric Probe for Mercuric Ion Contaminants in Aqueous Samples

引用

ACS Applied materials and Interfaces 2024年第30期16卷 39195-39205页

作者： Atayde, Eduardo C. Takenaka, Yasumasa Abe, Hideki Wu, Ming-Rou Wu, Kevin C.-W. Molecular Science and Technology Program Taiwan International Graduate Program Academia Sinica Department of Chemistry National Tsing Hua University Department of Chemical Engineering National Taiwan University Bioplastic Research Team RIKEN Center for Sustainable Resource Science Department of Chemical Engineering and Materials Science Yuan Ze University Department of Chemical Engineering Chung Yuan Christian University

Heavy metals are the most hazardous water pollutants, with severe health and environmental consequences. Among these, mercuric (Hg2+) ions are known to cause detrimental health issues in both humans and aquatic life. ... 详细信息

Heavy metals are the most hazardous water pollutants, with severe health and environmental consequences. Among these, mercuric (Hg²⁺) ions are known to cause detrimental health issues in both humans and aquatic life. Due to this, several analytical techniques have been devised to detect and quantify the amount of this ion. However, most of these require advanced instrumentation, prolonged analysis time, and sample preparation. In this study, a low-cost and highly reusable colorimetric probe was developed by grafting porphyrin to poly(ethylene terephthalate) sheets using an oxazoline polymer as covalent adhesive. Upon exposure to trace amounts of Hg²⁺ in solution, the fabricated material visually transitioned from faint brownish pink to green by the complexation mechanism. Additionally, the transparency of this probe allowed the quantitative spectrophotometric determination of the Hg²⁺ concentration in aqueous samples. It was also shown that the material is highly stable, which can be reused for more than 50 times without significant decline in its performance, hence, making it suitable for the onsite monitoring of mercuric ion contamination in different bodies of water. © 2024 The Authors. Published by American Chemical Society.

关键词： colorimetric probe mercuric ion oxazoline PET porphyrin

来源：评论

学校读者我要写书评

暂无评论

Transparent electromagnetic interference shielding materials using MXene

引用

Carbon Energy 2024年第11期6卷 322-345页

作者： Yanli Deng Yaqing Chen Wei Liu Lili Wu Zhou Wang Dan Xiao Decheng Meng Xingguo Jiang Jiurong Liu Zhihui Zeng Na Wu Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) School of Materials Science and Engineering Shandong UniversitylinanshandongChina Department of Mechanical Engineering The University of Hong KongHong KongSARChina Advanced Biomedical Instrumentation Centre Hong Kong SARChina State Key Laboratory of Crystal Materials Institute of Crystal Materials Shandong UniversityJinanShandongChina Xiaomi Communications Co.Ltd. School of Chemistry and Chemical Engineering Shandong UniversityJinanShandongChina

With the rapid advancement of terahertz technologies,electromagnetic interference(EMI)shielding materials are needed to ensure secure electromagnetic *** efforts have been devoted to achieving highly efficient EMI shielding films by enhancing flexibility,lightweight,mechanical robustness,and high shielding ***,the consideration of the optical properties of these shielding materials is still in its *** incorporating transparency,visual information from protected systems can be preserved for monitoring interior working conditions,and the optical imperceptibility allows nonoffensive and easy cover of shielding materials for both device and *** are many materials that can be applied to transparent EMI *** particular,two-dimensional transition metal carbide/nitrides(MXenes),possessing the advantages of superior conductivity,optical properties,favorable flexibility,and facile processibility,have become a great *** work reviews the recent research on developing highly efficient and optically transparent EMI shields in a comprehensive *** from MXenes,indium tin oxide,metal,carbon,and conductive polymers are covered,with a focus on the employment of MXene-based composites in transparent EMI *** prospects and challenges for the future development of MXene-based transparent EMI shields are *** work aims to promote the development of high-performance,optically transparent EMI shields for broader applications by leveraging MXenes.

关键词： electromagnetic waves transition metal carbides/nitrides transparent electromagnetic shielding materials

来源：评论

学校读者我要写书评

暂无评论

On the microstructural, mechanical, damping, wear properties of magnesium alloy AZ91-3 vol. % SiCP-3 vol. % fly ash hybrid composite and property correlation thereof

引用

Journal of Magnesium and Alloys 2025年第5期13卷 2374-2389页

作者： Gollapalli, Prince Pant, Mridul Chandra, A.R. Anil Surappa, M.K. Department of Materials Engineering Indian Institute of Science Karnataka Bangalore560012 India Department of Polymer & Process Engineering Indian Institute of Technology Roorkee Saharanpur Campus Saharanpur247001 India Department of Mechanical Engineering B.M.S. College of Engineering Karnataka Bangalore560019 India INSA Senior Scientist and Adjunct Professor National Institute of Advanced Studies Karnataka Bangalore560012 India

A combination of hard (SiCP) and soft (fly ash) particulate reinforcements could be a strategy to enhance combination of multiple properties of Magnesium and its alloys which otherwise suffer from low stiffness, low wear resistance, and many other critical properties. However, at present a comprehensive and robust map correlating different properties in particle-reinforced composites is much lacking. In this work, an industrial grade AZ91 magnesium alloy reinforced with hard SiC and soft fly ash particles (with 3 vol. % each), has been prepared using stir casting followed by hot extrusion at 325 ∘C with a ratio of 21.5. Microstructure of the hybrid composite was characterized using optical and scanning electron microscopes. The composite exhibited a reduction in average grain size from 13.6 to 7.1 µm, concomitantly an increase in Vickers hardness from 73 to 111 HV. The tension-compression yield asymmetry ratios of the unreinforced alloy and hybrid composite were 1.165 and 0.976, respectively indicating higher yield strength for the composite under compressive load. The composite exhibited 76% improvement in damping capacity under time sweep mode, and 28% improvement at 423 K under temperature sweep mode. The tribological characteristics of the composite under dry sliding conditions at sliding speeds and loads in the range of 0.5 to 1.5 m s-1 and 10 to 30 N, respectively showed higher wear resistance than the unreinforced alloy. The composite showed 23% improvement in sliding wear resistance at a load of 20 N and a speed of 1 m s-1. Finally, efforts have been made to understand the influence of one property on the other by developing statistical property correlation maps from the properties obtained in this study and from the literature. These maps are expected to help in the design of hybrid Metal Matrix Composites for a variety of targeted applications in different sectors. © 2025

关键词： Magnesium alloys

来源：评论

学校读者我要写书评

暂无评论

Effect of Sn addition on electrochemical activity of ribbons of Mg-Al-Ca anode material for rechargeable magnesium batteries fabricated by rapid solidification

引用

Keikinzoku/Journal of Japan Institute of Light Metals 2025年第1期75卷 9-13页

作者： Fukuta, Yoshitaka Kikura, Kensei Tsukeda, Tadayoshi Aida, Tetsuo Tabata, Hironobu Kurihara, Hideki Suzuki, Mayumi Program of Materials Science and Engineering Studies in Science and Engineering Graduate School of Science and Engineering University of Toyama 3190 Gofuku Toyama-shi Toyama930-8555 Japan Graduate School of Science and Engineering University of Toyama Toyama-shi Toyama Japan Faculty of Sustainable Design Academic Assembly University of Toyama Toyama-shi Toyama Japan CHUETSU METAL WORKS CO. LTD. Nakaniikawagun Toyama Japan Saitama Industrial technology Center Kawaguchi-shi Saitama Japan Department of Mechanical Systems Engineering Faculty of Engineering Toyama Prefectural University Imizu-shi Toyama Japan

Magnesium-based batteries are potential candidates for next-generation rechargeable batteries due to the divalent nature of magnesium cations and the natural abundance of magnesium resources. In this study, the electrochemical activity of Mg-6mass%Al-3mass%Ca anodes combined with Sn was investigated. Thin ribbons of the anode specimens were prepared by a single-roll rapid solidification method. The results showed that the electrochemical activity increased upon adding 1 mass% Sn, while it decreased for 3 mass% Sn. Based on the results of an X-ray diffraction analysis, the addition of Sn led to the formation of Mg2Sn and Ca2Sn phases, which increased the lattice distortion. Scanning electron microscopy observations indicated that these secondary phases were homogeneously distributed for 1 mass% Sn addition, while they were coarsely distributed for 3 mass% Sn. © 2025 The Japan Institute of Light Metals.

关键词： X ray diffraction analysis

来源：评论

学校读者我要写书评

暂无评论

Symmetric or asymmetric glide resistance to twinning disconnection?

引用

npj Computational materials 2022年第1期8卷 1615-1621页

作者： Mingyu Gong Houyu Ma Kunming Yang Yue Liu Jian-Feng Nie Jian Wang State Key Lab of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200240P.R.China Department of Materials Science and Engineering Monash UniversityClaytonVIC3800Australia Department of Mechanical&Materials Engineering University of Nebraska-LincolnLincolnNE68583USA

Successive gliding of twinning disconnections(TDs)creates three-dimensional twins in parent crystal and accommodates shear *** is generally recognized that TD is subject to the same Peierls stress as it glides forward or backward because of its dislocation character and the twofold rotation symmetry of the twin *** on atomistic simulations,we demonstrate that the glide of TDs may be subject to a symmetric or asymmetric resistance corresponding to step character,symmetric resistance for A/A type steps but asymmetric resistance for A/B type steps,where A and B represent crystallographic planes in twin and ***,we experimentally demonstrate that the asymmetric resistance results in asymmetric propagation and growth of twins in Mg alloys.

关键词： resistance deformation. steps

来源：评论

学校读者我要写书评

暂无评论

Great influence of demagnetization history on internal interaction and magnetization process of mischmetal-based magnets

引用

science China(Physics,Mechanics & Astronomy) 2025年第2期68卷 183-192页

作者： Dan Liu Jiefu Xiong Lichen Wang Xinqi Zheng Xin Ming Jiaying Jin Jiazheng Hao He Bai Zhenxing Li Tongyun Zhao Fengxia Hu Jirong Sun Jun Shen Baogen Shen Department of Physics Beijing Technology and Business UniversityBeijing 10048China Ningbo Institute of Materials Technology&Engineering Chinese Academy of SciencesNingbo 31521China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China Spallation Neutron Source Science Center Dongguan 523803China School of Mechanical Engineering Beijing Institute of Technology Beijing 100081China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 101408China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China

The magnetization process and corresponding magnetization curve are usually used to analyze the coercivity mechanism of NdFe-B based sintered ***,different demagnetization histories will seriously influence the magnetization curve,leading to an inaccurate understanding and analysis of magnetization *** this work,we investigated the magnetization behavior of multi-main phase(MMP)magnets with thermal demagnetized and alternating current demagnetized *** curves of initial magnetization process and demagnetization process of thermal demagnetized magnets reflect the movement of domain walls inside the grains and the magnetization interaction between the grains,*** is noted that the former process cannot represent the magnetization reversal of the entire magnet,which is not appropriate to analyze coercivity mechanism *** the recoil curves of both two processes of AC demagnetized magnets can illustrate the magnetization reversal of the entire grains and the interaction between ***-optical Kerr microscope shows that the grains of thermal demagnetized magnets are in multi-domain states,and the grains of AC demagnetized magnets are almost in singledomain *** walls of thermal demagnetized magnets move easily within the grains,which is more conducive to magnetization saturation in industrial *** addition,the minorloops of thermal demagnetized magnets can independently represent the transition of grains from multi-domain to single-domain and the demagnetization of single-domain grains,which is equivalent to characterizing the internal interactions by recoil *** investigation of magnetization characteristics of MMP sintered magnets starting from different demagnetized states is helpful to further understand the internal interaction and magnetic hardening mechanism.

关键词： permanent magnet demagnetization history magnetization reversal misch-metal rare earth

来源：评论

学校读者我要写书评

暂无评论

Variant selection in laser powder bed fusion of non-spherical Ti-6Al-4V powder

引用

Journal of materials science & Technology 2023年第16期147卷 56-67页

作者： Mohammadreza Asherloo Ziheng Wu Julian E.C.Sabisch Iman Ghamarian Anthony D.Rollett Amir Mostafaei Department of Mechanical Materials and Aerospace EngineeringIllinois Institute of Technology10 W 32nd StreetChicagoIL 60616United States Materials Engineering Division Lawrence Livermore National Laboratory7000 East AveLivermoreCA 94550United States Samuel Roberts Noble Microscopy Laboratory University of OklahomaNormanOK 73019United States School of Aerospace and Mechanical Engineering University of OklahomaNormanOK 73019United States Department of Materials Science and Engineering Carnegie Mellon UniversityPittsburghPA 15213United States

The presence ofα/αon priorβ/βgrain boundaries directly impacts the final mechanical properties of the titanium ***β/βgrain boundary variant selection of titanium alloys has been assumed to be unlikely owing to the high cooling rates in laser powder bed fusion(L-PBF).However,we hypothesize that powder characteristics such as morphology(non-spherical)and particle size(50–120μm)could affect the initial variant selection in L-PBF processed Ti-6Al-4V alloy by locally altering the cooling *** the high cooling rate found in L-PBF,results showed the presence ofβ/βgrain boundaryαlath growth inside two adjacent priorβ*** backscatter diffraction micrographs confirmed the presence ofβ/βgrain boundary variant selection,and synchrotron X-ray high-speed imaging observation revealed the role of the“shadowing effect”on the locally decreased cooling rate because of keyhole depth reduction and the consequentβ/βgrain boundaryαlath *** self-accommodation mechanism was the main variant selection driving force,and the most abundantα/αboundary variant was type 4(63.26°//[10553¯]).The dominance of Category IIαlath clusters associated with the type 4α/αboundary variant was validated using the phenomenological theory of martensite transformations and analytical calculations,from which the stress needed for theβ→αtransformation was calculated.

关键词： Variant selection Phase formation Additive Manufacturing Hydride-dehydride powder Texture analysis Electron backscattered diffraction

来源：评论

学校读者我要写书评

暂无评论

Effects of strain rate on austenite stability and mechanical properties in a 5Mn steel

引用

Journal of Iron and Steel Research International 2022年第2期29卷 316-326页

作者： Yong-gang Yang Wang-zhong Mu Xiao-qing Li Hai-tao Jiang Mai Wang Zhen-li Mi Xin-ping Mao Beijing Advanced Innovation Center for Materials Genome Engineering National Engineering Research Center for Advanced Rolling TechnologyUniversity of Science and Technology BeijingBeijing100083China Department of Materials Science and Engineering KTH Royal Institute of TechnologyStockholm10044Sweden Department of Mechanical Engineering The University of Hong KongHong Kong999077China

The austenite stability and the mechanical properties in a typical medium Mn grade steel,i.e.,5Mn steel,were investigated under a wide range of strain rates through the combination of experimental and theoretical *** obtained results indicate that austenite is more stable at a high strain rate,which is due to the suppression of the austenite to martensite *** suppression is attributed to the increased stacking fault energy and the high deformation energy ***,the suppression of martensitic transformation also leads to the decrease in the ultimate tensile strength and the uniform *** to the increase in an adiabatic heating temperature,an increase in the uniform elongation is acquired at a high strain *** obtained fundamental study results shed light on a wide application of the medium Mn steel under different strain rate conditions.

关键词： Medium Mn steel Austenite stability Microstructure mechanical property Strain rate

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：