检索结果-南通市图书馆

On the formation of shear bands in a metallic glass under tailored complex stress fields

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第18期52卷 112-117页

作者： S.H.Chen T.Li W.J.Chang H.D.Yang J.C.Zhang H.H.Tang S.D.Feng F.F.Wu Y.C Wu School of Mechanical Engineering Hefei University of TechnologyHefei 230009China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China School of Materials Science and Engineering Liaoning University of TechnologyJinzhou 121001China School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China

The formation of shear bands in metallic glasses(MGs)was examined by tailoring localized complex stress fields(LCSFs).The findings have shown that the LCSFs in MGs can increase the localization of strained atoms and accelerate the release of accumulated deformation energy for initiating a shear band in confined and thin-layered *** findings not only add more knowledge to the formation mechanisms of shear bands in MGs,but also provide possible rationale for the discrepancies in the mechanical properties of different-sized *** compared with the bulk samples,the higher strength and larger elastic limits in nanoscaled MGs could be attributed to the elimination of stress-concentrators,which can serve as LCSFs.

关键词： Localized complex stress field Shear band metallic glass Molecular dynamics simulation Size effect

Aging and rejuvenation during high-temperature deformation in a metallic glass

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2022年第10期65卷 93-100页

作者： Langting Zhang Yunjiang Wang Yong Yang Jichao Qiao School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical University(NPU)Xi’an 710072China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China Department of Mechanical Engineering College of EngineeringCity University of Hong KongHong Kong 999077China Department of Materials Science and Engineering College of EngineeringCity University of Hong KongHong Kong 999077China Innovation Center NPU-ChongqingChongqing 401135China

High-temperature deformation has been demonstrated as an effective measure to rejuvenate and optimize the mechanical properties of metallic glasses(MGs).Clarifying the competition between aging and rejuvenation during high-temperature deformation is helpful in rejuvenating MGs *** of aging and rejuvenation in a La_(30)Ce_(30)Ni_(10)Al_(20)Co_(10)MG were investigated via high-temperature deformation and mechanical *** coupling of thermal history,aging,and mechanical disordering determines the transient deformation and the structural state of *** stress overshoot and anelastic deformation induce structural rejuvenation,increasing the concentration of defects and erasing thermal ***,the eventually steady-state condition is dependent on ambient temperature and strain rate instead of the initial ***,the one-to-one relationship between defect concentration and strain rate clarifies the structural nature of rejuvenation in amorphous *** a relationship also contributes toward a comprehensive understanding of the structural rejuvenation behavior in amorphous materials.

关键词： metallic glass aging rejuvenation homogenous flow free volume

同方期刊数据库

Structure Heterogeneity in metallic glass: Modeling and Experiment

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2014年第6期30卷 560-565页

作者： H.B.Ke J.F.Zeng C.T.Liu Y.Yang Centre for Advanced Structural Materials Department of Mechanical and Biomedical EngineeringCity University of Hong Kong

Despite the great efforts dedicated to metallic glasses （MGs）, their structure still remains a mystery to be understood. With comparison to the existing mJciomechanical models, such as the free-volume and shear transformation zone （STZ） models, we first discuss in this article our recently proposed ＇core-shell＇ model, which contains a solid-like matrix and liquid-like inclusions. This serves as the theoretical basis to understand the structural heterogeneity in MGs in our analytical framework. After that, a scanning ultrafast nanoindentation technique is used to map out the structure heterogeneity in a Zr-based bulk metallic glass （BMG）. With these ongoing research efforts, we hope that more research work could be stimulated in the pursuit of the structure-property relation in MGs.

关键词： metallic glass Structure heterogeneity Nanoindentation Core-shell model

Thermal effects and evolution of the defect concentration based on shear modulus relaxation data in a Zr-based metallic glass

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第8期29卷 133-136页

作者： Qi Hao Ji-Chao Qiao E V Goncharova G V Afonin Min-Na Liu Yi-Ting Cheng V A Khonik School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 710072China Department of General Physics Voronezh State Pedagogical UniversityLenin Street 86Voronezh 394043Russia

A relationship between thermal effects and relaxation of the high-frequency shear modulus upon heat treatment of bulk Zr48(Cu5/6Ag1/6)44Al8 metallic glass is *** relationship is attributed to the relaxation of a interstitial-type defect system frozen-in from the melt upon glass *** data show that thermal effects occurring on heating include heat release below the glass transition temperature,heat absorption above it and heat release caused by *** equation derived within the Interstitialcy theory can be used to calculate the shear modulus relaxation using the calorimetric *** obtained results are used to trace the defect concentration as functions of temperature and thermal prehistory.

关键词： shear modulus metallic glass structural relaxation interstitialcy theory

Dynamic mechanical behavior of a Zr-based bulk metallic glass during glass transition and crystallization

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2009年第1期28卷 72-76页

作者： CHAO Qi WANG Qing DONG Yuanda Institute of Materials Science Shanghai University Shanghai 200072 China

The dynamic mechanical behaviors of the Zr41Ti14Cu12.5Ni8Be22.5Fe2 bulk metallic glass （BMG） during continuous heating at a constant rate were investigated. The glass transition and crystallization of the Zr-based BMG were thus characterized by the measurements of storage modulus E′ and internal friction Q^-1. It was found that the variations of these dynamic mechanical quantities with temperature were interre-lated and were well in agreement with the DSC trace obtained at the same heating rate. The origin of the first peak in the internal friction curve was closely related to the dynamic glass transition and subsequent primary crystallization. Moreover, it can be well described by a physical model, which can characterize atomic mobility and mechanical response of disordered condense materials. In comparison with the DSC trace, the relative position of the first internal friction peak of the BMG was found to be dependent on its thermal stability against crys-tallization.

关键词： metallic glass dynamic mechanical behavior internal friction glass transition crystallization

Efficient nanostructured heterogeneous catalysts by electrochemical etching of partially crystallized Fe-based metallic glass ribbons

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第2期61卷 159-168页

作者： Qiaoyue Zhang Shun-Xing Liang Zhe Jia Wenchang Zhang Weimin Wang Lai-Chang Zhang School of Engineering Edith Cowan University270Joondalup DriveJoondalupPerthWA 6027Australia Technical Chemistry I and Center for Nanointegration Duisburg-Essen(CENIDE) University of Duisburg-EssenUniversitaetsstrasse 7Essen 45141Germany School of Mechanical and Manufacturing Engineering.UNSW Sydney SydneyNSW 2052Australia Ji'an Ecological Environment Monitoring Center of Jiangxi Province Ji'anJiangxi Province 343000China School of Materials Science and Engineering.Shandong University JinanShandong Province 250061China

Although an increasing interest has been attracted to further develop heterostructured catalysts from metallic glasses(MGs) by heat treatment, overcoming surface oxidation effect is still a critical problem for such environmental catalysts. Herein, a short-time electrochemical etching of partially crystallized Febased ribbons in 0.3 M H3 PO4 electrolyte enables the formation of honeycomb-like nanoporous structure as effective catalytic active sites in Fenton-like process. Studies of structure and surface morphologies reveal that the formation of nanoporous structure by potentiostatic etching originates from electrochemical potential difference of nanocrystals(a-Fe(Si) and Fe2 B) and residual amorphous phase in partially crystallized ribbons, where Fe2 B having a lower open circuit potential tends to be selectively ***, thin oxide layer after electrochemical etching exposes more active sites for H2 O2 activation and provides an effective protection of nanocrystals from massive loss during etching. Investigation of optimal processing conditions suggests that the selection of electrolyte plays an important role;dye degradation rates of etched ribbons in HNO3 and Na2 SO4 electrolytes can also achieve at least 2 times higher than that of as-annealed ribbons. This work holds the promise to develop novel environmental catalysts by effective electrochemical etching of partially crystallized ribbons.

关键词： metallic glass Nanoporous structure Crystallization Electrochemical etching Selective dissolution

Crystallization Study of Cu_(56)Zr_7Ti_(37) metallic glass by Electrical Resistivity Measurement

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2011年第3期27卷 275-279页

作者： Ansu J.Kailath Kalpalata Dutta Thomas C. Alex Amitava Mitra National Metallurgical Laboratory

In this paper, the crystallization behaviour of amorphous Cu56Zr7Ti37 alloy using thermal electrical resistivity （TER） and differential scanning calorimetry （DSC） studies has been described. Isochronal TER and DSC measurements indicate that crystallization occurs in two stages. Isothermal crystallization studies of the alloy by TER show that the kinetics conforms to Johnson-Mehl-Avrami model. Avrami exponents derived from kinetics, between 1.1 and 1.2, imply that the crystallization processes are diffusion controlled with near zero nucleation. Activation energy has been found to increase with the transformed volume fraction. A plausible explanation has been presented by separating the contributions due to nucleation and crystal growth towards total activation energy.

关键词： metallic glass Crystallization Electrical resistivity Avrami exponent Activation energy

Effect of Cu content on microstructure and mechanical properties of in-situ β phases reinforced Ti/Zr-based bulk metallic glass matrix composite by selective laser melting(SLM)

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第8期67卷 174-185页

作者： Xuehao Gao Xin Lin Qiaodan Yan Zihong Wang Xiaobin Yu Yinghui Zhou Yunlong Hu Weidong Huang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an710072China Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design MUT ChinaNorthwestern Polytechnical UniversityXi'an710072China

In this study,non-toxic in-situβphases of reinforced Ti/Zr-based bulk metallic glass matrix composites(BMGCs)of(Ti_(0.65)Zr_(0.35))100-xCux(x=5,10,15 at.%)are fabricated via selective laser *** effect of Cu content on phase formation,microstructure,and mechanical properties is *** average volume fraction and width of theβphase decreases with increasing Cu content,while a more amorphous phase and the(Ti,Zr)_(2)Cu phase *** the center zone of the molten pool,theβphase grows in the direction of the temperature gradient,and the amorphous phase distributes among theβ*** occurs using:sphere morphology(for x=5),a more continuous elongated sphere and network morphology(for x=10),and network morphology(for x=15),*** the edge zone of the molten pool,due to the smaller cooling rate and the existence of a partially molten zone,theβphase becomes coarser,and an amorphous phase forms for more continuous ***,the hardness improves significantly with increasing Cu *** crack is found for x=*** the average volume fraction of theβphase for x=5 is about 90%,the compression yield strength is 1386±64 MPa,reaching to an average level of conventionally fabricated counterparts,due to finer microstructure,and twinning and martensitic transformation of theβphase.

关键词： metallic glass Amorphous phase βPhase Bulk metallic glass matrix composites(BMGCs) Additive manufacturing(AM) Selective laser melting(SLM)

Phase transformation behavior of a dual-phase nanostructured Fe-Ni-B-Si-P-Nb metallic glass and its correlation with stress-impedance properties

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2023年第8期42卷 2757-2766页

作者： Jia-Cheng Ge Ai-Hua Liu Zhen-Duo Wu Yao Gu Yu-Bin Ke An-Ding Wang Yang Ren Song Tang Hui-Qiang Ying He Zhu Xun-Li Wang Si Lan Herbert Gleiter Institute of Nanoscience School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Department of Physics City University of Hong KongHong Kong999077China City University of Hong Kong(Dongguan) Dongguan 523000China Center for Neutron Scattering City University of Hong Kong Shenzhen Research InstituteShenzhen 518057China Spallation Neutron Source Science Center Dongguan 523803China Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology Dongguan 523803China School of Materials Science and Engineering Dongguan University of TechnologyDongguan 523808China

A study of the phase transformation process of a Fe-Ni-B-Si-P-Nb metallic glass using a suite of advanced characterization tools is *** electron microscopy(TEM)and small angle neutron scattering(SANS)experiments show that the as-spun metallic glass ribbon has a dual-phase structure with bcc nanoclusters of a size of 2-3 *** situ high-energy X-ray diffraction(XRD)reveals a three-stage crystallization process when heating the metallic glass into supercooled liquid *** isothermal annealing experiment shows the nanoclusters grow instantly without *** easy formation and phase stability of the nanoclusters are due to the low interfacial energy between the amorphous matrix and clusters,as real space analysis shows that the nanoclusters and the amorphous matrix share similar short-to-mediumrange *** further find that the dual-phase structure reduces local magneto-anisotropy and enhances effective magnetic permeability,resulting in an excellent stressimpedance effect without sacrificing *** work sheds light on the structure-property engineering of soft magnetic metallic glasses and provides a foundation for developing novel magnetic functional materials with nanostructured dual-phases.

关键词： Soft-magnetic property metallic glass Phase transformation Synchrotron and neutron scattering Stressimpedance(SI)