检索结果-南通市图书馆

Effect of Ni content on the wear behavior of Al-Si-Cu-Mg-Ni/SiC particles composites

International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 374-383页

作者： Yanyu Liu lina jia Wenbo Wang Zuheng Jin Hu Zhang School of Materials Science and Engineering Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315100China Qingdao Research Institute of Beihang University Qingdao 266000China Research Institute for Frontier Science Beihang UniversityBeijing 100191China

In recent years,the addition of Ni has been widely acknowledged to be capable of enhancing the mechanical properties of Al-Si alloys.However,the effect of Ni on the wear behaviors of Al-Si alloys and Al matrix composites,particularly at elevated temperat-ures,remains an understudied area.In this study,Al-Si-Cu-Mg-Ni/20wt%SiC particles(SiCp)composites with varying Ni contents were prepared by using a semisolid stir casting method.The effect of Ni content on the dry sliding wear behavior of the prepared compos-ites was investigated through sliding tests at 25 and 350℃.Results indicated that theθ-Al_(2)Cu phase gradually diminished and eventually disappeared as the Ni content increased from 0wt%to 3wt%.This change was accompanied by the formation and increase inδ-Al_(3)CuNi andε-Al_(3)Ni phases in microstructures.The hardness and ultimate tensile strength of the as-cast composites improved,and the wear rates of the composites decreased from 5.29×10^(−4)to 1.94×10^(−4)mm^(3)/(N∙m)at 25℃and from 20.2×10^(−4)to 7×10^(−4)mm^(3)/(N∙m)at 350℃with the increase in Ni content from 0wt%to 2wt%.The enhancement in performance was due to the presence of strengthening network structures and additional Ni-containing phases in the composites.However,the wear rate of the 3Ni composite was approximately two times higher than that of the 2Ni composite due to the fracture and debonding of theε-Al_(3)Ni phase.Abrasive wear,delamination wear,and oxidation wear were the predominant wear mechanisms of the investigated composites at 25℃,whereas delamination wear and oxid-ation wear were dominant during sliding at 350℃.

关键词： Al matrix composite microstructure sliding test high temperature wear mechanism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Morphological Heredity of Intermetallic Nb_(5)Si_(3)Dendrites in Hypereutectic Nb-Si Based Alloys via Non-Equilibrium Solidification

引用

Chinese Journal of Mechanical Engineering 2022年第5期35卷 393-400页

作者： Yueling Guo lina jia Wenjun Lu Hu Zhang School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Research Center of Light‑alloy Materials Frontier Institute of Science and Technology InnovationBeihang UniversityBeijing 100191China Max-Planck-Institut für Eisenforschung Max‑Planck‑Straße 140237 DüsseldorfGermany

For hypereutectic Nb-Si based alloys,primary Nb_(5)Si_(3)phases typically grow in a faceted mode during equilibrium or near-equilibrium solidification,which damages the ductility and toughness.To address this issue,here we artificially manipulate the growth morphology of Nb_(5)Si_(3)using electron beam surface melting(EBSM)and subsequent annealing treatments.Results show that such a non-equilibrium solidification pathway enables the transition from faceted growth to non-faceted dendritic growth of Nb_(5)Si_(3),along with evident microstructure refinement,generation of metastableβ-Nb_(5)Si_(3)phases and elimination of chemical segregation.The transformation fromβ-Nb_(5)Si_(3)toα-Nb_(5)Si_(3)and Nb solid solution(Nbss)particles is triggered by the annealing treatment at 1450°C for 5 h.Also,we find the annealing-mediated formation of inherited Nb_(5)Si_(3)dendrites that maintain the dendritic morphology of the original as-solidifiedβ-Nb_(5)Si_(3)dendrites.This work thus provides a feasible routine to obtain thermally stable and refinedα-Nb_(5)Si_(3)dendrites in hypereutectic Nb-Si based alloys.

关键词： Nb-Si alloy Intermetallics Nb_(5)Si_(3) Rapid solidification Dendritic growth

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Behaviors and interactions of strengthening and constraint for ductile Nbss matrix in Nb-Si based alloys

引用

Progress in Natural Science:Materials International 2022年第2期32卷 215-225页

作者： Yu Wang lina jia Chengtong Ye Guangxin Sun Hu Zhang School of Materials Science and Engineering Beihang University Research Center of Light-alloy Materials Frontier Institute of Science and Technology Innovation Beihang University Ningbo Institute of Technology (NIT) Beihang University Department of Materials Science and Engineering National University of Singapore

The ductile matrix in composites could be strengthened by incorporating brittle inclusions,while the constraint effect for matrix would become more obvious and detrimental to material toughening.The balance between strengthening and toughening was crucial to achieve excellent comprehensive mechanical properties.Upon the basis of microstructure of Nb-Si in situ composites,a unit rectangular cell containing elastic and isotropic Nb5Si3particles was modeled,the Niobium solid solution(Nbss) matrix according with the Ramberg-Osgood constitutive relation was recognized as elastic-plastic.For Nb-Si based alloys,the effects of volume fractions of Nb5Si3reinforcements,stress states and interfacial characteristics on the stress-strain field,flow localization and damage evolution were investigated by the finite element method(FEM).Further,the normalized work of rupture(χ) was calculated quantitatively as a function of volume fractions of Nb5Si3phase as well as yield strength of Nbss matrix.These results would contribute to acquire more fundamental understanding of the strengthening and constraint effects which were exerted by Nb5Si3reinforcements to ductile Nbssmatrix,also an instructive guidance for the optimum design of Nb-Si based alloys.

关键词： Nb-Si based Alloys Microstructure Fracture characteristics Matrix strengthening Plastic constraint Finite element method

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Effects of minor B additions on tensile strength, fracture toughness and oxidation resistance of Nb–Si based alloys

引用

Progress in Natural Science:Materials International 2022年第2期32卷 248-258页

作者： Guangxin Sun lina jia Yu Wang Zuheng Jin Hu Zhang School of Materials Science and Engineering Beihang University

The effects of minor additions of B on microstructure,ambient tensile strength,fracture toughness and hightemperature oxidation resistance of Nb-Si based alloys were investigated.The added contents were designed as 0.05,0.10 and 0.20 at.%.The results show constituent phases in 0.05 B and 0.20 B alloys were Nbss,α-NbSi;while only 0.10 B alloy consisted of γ-NbSi.Minor B was prioritized into Nbss and redundant one dissolved into silicide enhanced volume fraction of the silicide.With increasing concentrations of boron,the microstructure was refined at first and then coarsened,while the tensile strength was enhanced remarkably.Compared with other two alloys,the 0.10 B alloy containing γ-NbSishows both the best fracture toughness and oxidation resistance.The important roles of γ-NbSiin balancing overall properties are emphasized.

关键词： Nb-Si based Alloys Directional solidification Tensile strength Fracture toughness Oxidation resistance

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Sulfur-deficient CoNi_(2)S_(4)nanoparticles-anchored porous carbon nanofibers as bifunctional electrocatalyst for overall water splitting

引用

Frontiers of Chemical Science and Engineering 2023年第11期17卷 1707-1717页

作者： Gaohui Du Yi Fan lina jia Yunting Wang Yawen Hao Wenqi Zhao Qingmei Su Bingshe Xu Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan 030000China Materials Institute of Atomic and Molecular Science Shaanxi University of Science and TechnologyXi’an 710021China

Water electrolysis technology is considered to be one of the most promising means to produce hydrogen.Herein,aiming at the problems of high overpotential and slow kinetics in water splitting,N-doped porous carbon nanofibers-coupled CoNi_(2)S_(4)nanoparticles are prepared as bifunctional electrocatalyst.In the strategy,NaCl is used as the template to prepare porous carbon nanofibers with a large surface area,and sulfur vacancies are created to modulate the electronic structure of CoNi_(2)S_(4).Electron spin resonance confirms the formation of abundant sulfur vacancies,which largely reduce the bandgap of CoNi_(2)S_(4)from 1.68 to 0.52 eV.The narrowed bandgap is conducive to the migration of valence electrons and decreases the charge transfer resistance for electrocatalytic reaction.Moreover,the uniform distribution of CoNi_(2)S_(4)nanoparticles on carbon nanofibers can prevent the aggregation and facilitate the exposure of electrochemical active sites.Therefore,the composite catalyst exhibits low overpotentials of 340 mV@100 mA·cm^(-2)for oxygen evolution reaction and 380 mV@100 mA·cm^(-2)for hydrogen evolution reaction.The assembled electrolyzer requires 1.64 V to achieve 10 mA·cm^(-2)for overall water-splitting with good long-term stability.The excellent performance results from the synergistic effect of porous structures,sulfur deficiency,nitrogen doping,and the well-dispersed active component.

关键词： nanoparticle sulfur vacancy porous carbon nanofiber transition metal sulfides electrolysis

来源：

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

Progress in Nb-Si ultra-high temperature structural materials:A review

引用

Journal of Materials Science & Technology 2023年第18期149卷 127-153页

作者： Wei Liu Shuai Huang Chengtong Ye lina jia Yongwang Kang jiangbo Sha Bingqing Chen Yu Wu Huaping Xiong 3D Printing Research and Engineering Technology Center Beijing Institute of Aeronautical MaterialsBeijing 100095China School of Materials Science and Engineering Beihang UniversityBeijing 100191China Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical MaterialsBeijing 100095China

Nb-Si based alloys have the greatest potential to replace nickel-based superalloys and become a new gen-eration ultra-high temperature structural material with service temperature of 1200-1400℃ due to their high melting point,high stiffness,low density,and attractive specific mechanical properties at elevated temperatures.This article reviewed the recent progress in the development of Nb-Si based refractory al-loys.Special attention was paid to the property characteristics,preparation techniques,alloying effects,oxidation resistance and fabrication of Nb-Si based alloy components.Thereafter,the trend of develop-ment in the future was forecasted,including:Optimization of the composition and microstructure of Nb-Si based alloys to achieve a balance of mechanical properties;Comprehensive properties evaluation for Nb-Si based alloys to accumulate sufficient data for engineering applications;Development of practical preparation technology for Nb-Si based alloy components with complex shapes;New multilayer compos-ite coatings for Nb-Si based alloy;Joining technology of Nb-Si alloy to itself and to superalloy.

关键词： Nb-Si based alloys Alloying Mechanical property Fracture toughness Oxidation behavior Coating

来源：

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

Elucidating the Role of Mass Transfer in Electrochemical Redox Reactions on Electrospun Fibers

引用

Transactions of Tianjin University 2023年第5期29卷 313-320页

作者： Yan Li Ziwang Kan lina jia Dan Zhang Yan Hong Jingjing Liu Haibo Huang Siqi Li Song Liu College of Chemistry Chemical Engineering and Resource UtilizationNortheast Forestry UniversityHarbin 150040China Department of Materials Science and Engineering Northeast Forestry UniversityHarbin 150040China

Mass transfer can tune the surface concentration of reactants and products and subsequently infl uence the catalytic perfor-mance.The morphology of nanomaterials plays an important role in the mass transfer of reaction microdomains,but related studies are lacking.Herein,a facile electrospinning technique utilizing cellulose was employed to fabricate a series of carbon nanofi bers with diff erent diameters,which exhibited excellent electrochemical nitrate reduction reaction and oxygen evolu-tion reaction activities.Furthermore,the microstructure of electrocatalysts could infl uence the gas-liquid-solid interfacial mass transfer,resulting in diff erent electrochemical performances.

关键词： Mass transfer Electrospinning Electrochemical nitrate reduction reaction Oxygen evolution reaction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于AHP和GIS的舟曲地质灾害易发性评价

引用

西北地质 2024年第1期57卷 23-33页

作者：贾丽娜陈世昌甘肃省地下水工程及地热资源重点实验室甘肃省地质环境监测院甘肃兰州730050

舟曲县是中国罕见的滑坡、泥石流地质灾害高发区,其防灾减灾工作具有一定的挑战性。依托舟曲县1∶50000地质灾害风险调查工作,深入分析孕灾地质条件,选取地质灾害频率比、地质灾害面积模数比、地质灾害体积模数比、坡度、坡度变化率、... 详细信息

舟曲县是中国罕见的滑坡、泥石流地质灾害高发区,其防灾减灾工作具有一定的挑战性。依托舟曲县1∶50000地质灾害风险调查工作,深入分析孕灾地质条件,选取地质灾害频率比、地质灾害面积模数比、地质灾害体积模数比、坡度、坡度变化率、坡形、切割深度、沟壑密度、岩土体类型、地质构造、植被指数11个评价因子,建立AHP评价模型,确定各因子权重,运用GIS平台综合评价舟曲县地质灾害易发性。结果显示:舟曲县地质灾害极高易发区和高易发区的面积分别为68.98 km^(2)、390.9 km^(2),分别占县域总面积的2.29%和12.97%,主要分布在人员财产集中的白龙江流域、石门沟流域、拱坝河流域中下游和博峪河流域舟曲段中部区域;中易发区、低易发区对应的面积分别为1166.21 km^(2)和1387.76 km^(2)。研究成果为舟曲县城镇整体规划和地质灾害防治提供决策参考。

关键词：地质灾害易发性评价孕灾地质条件 AHP 舟曲县

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Precipitation behavior and properties of extruded 7136 aluminum alloy under different aging treatments

引用

Chinese Journal of Aeronautics 2021年第2期34卷 612-619页

作者： Huiyan LI lina jia jiangnan HUANG Yue MA School of Materials Science and Engineering Beihang UniversityBeijing 100083China

In this work, the mechanical properties and electrical conductivity of the extruded 7136 aluminum alloy treated by single-stage aging treatment(T6), retrogression and re-aging treatment(RRA), and multiple retrogression and re-aging treatment have been investigated by means of hardness measurements, electrical conductivity tests and tensile tests. The results have shown that the properties of the 7136 alloy such as hardness, tensile strength and electrical conductivity were sensitive to retrogression time(within 90 min). With prolonging the retrogression time, the tensile strength was enhanced first and then decreased, yet the electrical conductivity was continuously increased. The 60 min-treated alloy performed the highest tensile strength(716 MPa), whereas the 90 min-treated alloy possessed the highest electrical conductivity(33.95%IACS). Compared with the T6-treated alloy, the tensile strength and electrical conductivity were improved by 3.3%and 18.9%, respectively. The electrical conductivity showed an obvious increase with repetitious times of the RRA treatment. After 3 RRA60 treatment, a good combination of tensile strength(705 MPa) and electrical conductivity(33.20%IACS) can be obtained. Compared with the T6 condition, the tensile strength and electrical conductivity were improved by 1.7% and 16.3%, respectively. The mechanism of microstructure evolution under different aging treatments has been discussed in detail.

关键词： 7136 aluminum alloy Electrical conductivity Mechanical properties Microstructure Retrogression and re-aging

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Single track and single layer formation in selective laser melting of niobium solid solution alloy

引用

Chinese Journal of Aeronautics 2018年第4期31卷 860-866页

作者： Yueling GUO lina jia Bin KONG Na WANG Hu ZHANG School of Materials Science and Engineering Beihang University

Selective laser melting（SLM） was employed to fabricate Nb-37 Ti-13 Cr-2 Al-1 Si（at%）alloy, using pre-alloyed powders prepared by plasma rotating electrode processing（PREP）. A series of single tracks and single layers under different processing parameters was manufactured to evaluate the processing feasibility by SLM, including laser power, scanning speed, and hatch distance.Results showed that continuous single tracks could be fabricated using proper laser powers and scanning velocities. Both the width of a single track and its penetration depth into a substrate increased with an increase of the linear laser beam energy density（LED）, i.e., an increase of the laser power and a decrease of the scanning speed. Nb, Ti, Si, Cr, and Al elements distributed heterogeneously over the melt pool in the form of swirl-like patterns. An excess of the hatch distance was not able to interconnect neighboring tracks. Under improper processing parameters, a balling phenomenon occurred, but could be eliminated with an increased LED. This work testified the SLMprocessing feasibility of Nb-based alloy and promoted the application of SLM to the manufacture of niobium-based alloys.

关键词： Additive manufacturing Melt pool Niobium alloy Powder metallurgy Selective laser melting

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

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：