检索结果-南通市图书馆

Abnormal grain growth induced byδ→γphase transformation in Fe-based shape memory alloys

Journal of Materials Science & Technology 2024年第5期172卷 196-201页

作者： Huabei Peng Liqiu Yong Gaixia Wang Jiazhen Yan Bing Xu yuhua wen School of Mechanical Engineering Sichuan UniversityChengdu 610065China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu 610041China

Grain boundaries,including low-angle,high-angle,and coinci-dence boundaries,are intrinsic interfaces in polycrystalline *** heat-treatment at sufficiently high temperatures,grain boundary migration occurs because the grain boundaries are ther-modynamically ***,grain growth occurs due to a decrease in grain boundary area after heat-treatment[1].In general,there are two types of grain growth:normal grain growth,where grains grow uniformly,and abnormal grain growth,where one or a few grains selectively grow and engulf surround-ing smaller grains,leading to the formation of large grains,some-times several millimeters or greater in size[2].The classical tech-nique to achieve abnormal grain growth is the strain-annealing method,which involves subjecting the material to a small strain followed by annealing[3,4].This method has been reported to ob-tain single-crystal wires or plates[1].Additionally,abnormal grain growth can be achieved by plastic straining at high temperatures,resulting in the fabrication of large grains or single crystals[5].However,the above methods are not applicable to components with complicated shapes due to the inevitable deformation ***,Omori et *** a simply method of abnor-mal grain growth to fabricate ultra-large grains,even single crys-tals,in Cu-Al-Mn[1],Fe-Mn-Al-Ni[2],and Fe-Mn-Al-Ni-Cr[6]*** method involves applying cyclic heat treatment between a high temperature BCC single-phase region and a low tempera-ture BCC+FCC two-phase region[1,2,6-12].Note that the cyclic heat treatment resulted in the formation of BCC sub-grain struc-tures responsible for abnormal grain growth[1,2,6-12].In addition,Yang et *** that abnormal grain growth occurred at above 900℃,and large-grains,even single crystals,were obtained only through annealing cast Cu-based polycrystalline alloys contained coherent nano-particles[13,14].Notably,the cyclic heat treatment and annealing cast alloys are deform

关键词： grain alloys deformation

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

2011-2021年甘肃省生态环境质量综合评价及时空演变特征分析

引用

干旱区资源与环境 2024年第6期38卷 110-119页

作者：温煜华中共甘肃省委党校(甘肃行政学院)社会和生态文明教研部兰州730070

以甘肃省14个市州为评价单元,耦合PSR模型和InVEST模型对2011-2021年甘肃省生态环境质量进行评价,并分析其演变规律及影响因素。结果表明:运用PSR模型和InVEST模型评价的生态环境质量格局非常相似,PSR模型在分析人类活动对环境的影响方... 详细信息

以甘肃省14个市州为评价单元,耦合PSR模型和InVEST模型对2011-2021年甘肃省生态环境质量进行评价,并分析其演变规律及影响因素。结果表明:运用PSR模型和InVEST模型评价的生态环境质量格局非常相似,PSR模型在分析人类活动对环境的影响方面更具优势,InVEST模型在刻画生态环境质量分异方面更精细,两种方法具有优势互补、相互验证的功效。从时间格局来看,2011-2021年甘肃省生态环境质量经历了从较差-一般-良-优的持续向好转变过程,生境质量指数也逐年提高。1)由于人类活动对生态环境造成的压力不断减少。2)人类采取有效措施消除了对生态环境的负面影响,使得生态环境治理成果显著。从空间格局来看,以重工业为主的资源型城市生态压力大于农业型城市。基于PSR模型和InVEST模型计算的生态环境综合指数和生境质量都是自南向北逐渐降低。甘肃省生态环境质量变化是自然环境与人类活动叠加的体现,也是生态环境演变的内在机理。

关键词：生态环境评价生态环境治理 PSR模型 InVEST模型甘肃省

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

冷轧Al-4Ti-1B变质剂对ZL205A合金组织和力学性能的影响

引用

热加工工艺 2024年第15期53卷 59-65页

作者：赵志豪邓高生徐小林文玉华四川大学机械工程学院四川成都610065 重庆衡山机械有限责任公司重庆404100

研究了冷轧对Al-4Ti-1B华夫块变质剂中TiAl3和TiB2相尺寸和形态的影响,及其对ZL205A合金组织和力学性能的影响。结果表明,冷轧能将Al-4Ti-1B变质剂中的杆状TiAl3相碎化成块状,导致TiAl3相尺寸减小,数量显著增加。与未冷轧Al-4Ti-1B华夫... 详细信息

研究了冷轧对Al-4Ti-1B华夫块变质剂中TiAl3和TiB2相尺寸和形态的影响,及其对ZL205A合金组织和力学性能的影响。结果表明,冷轧能将Al-4Ti-1B变质剂中的杆状TiAl3相碎化成块状,导致TiAl3相尺寸减小,数量显著增加。与未冷轧Al-4Ti-1B华夫块变质剂细化ZL205A合金的晶粒相比,减少1/3加入量的冷轧Al-4Ti-1B华夫块变质剂实现了相当的晶粒细化效果。经T6热处理后,减少1/3加入量的冷轧Al-4Ti-1B华夫块变质合金的塑性比未冷轧华夫块变质合金高4%,但其抗拉强度降低5 MPa。其强度的降低可归因于固溶在基体中Ti原子数量减少导致的Al2Cu强化相数量的减少和尺寸的增大。

关键词： ZL205A铝合金 Al-4Ti-1B变质剂冷轧晶粒细化力学性能

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

Degeneration and rejuvenation of shape memory effect associated with the precipitation of coherent nano-particles in a Co-Ni-Si shape memory alloy

引用

Journal of Materials Science & Technology 2021年第17期76卷 150-155页

作者： Huabei Peng Dian Wang Qi Liao yuhua wen School of Mechanical Engineering Sichuan UniversityChengdu 610065China

In a solution treated Co-20Ni-6Si shape memory alloy,coherent nano-particles were precipitated after annealing at 873 K for 1 min,but the shape memory effect almost *** is attributed to that the coherent nano-particles not only suppressed the stress-induced face-centered cubic to close-packed hexagonal martensite transformation but also damaged the crystallographic reversibility of reverse martensite *** further annealing at 1073 K for 1 min,the shape memory effect was rejuvenated owing to the dissolution of ***,the recovery strain significantly increased to5.1%from the solution treatment of 3.1%after annealing at 1073 K for 1 min.

关键词： Shape memory alloys Martensitic phase transformation Defects Coherent nano-particles

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

Wear Resistance of Austenitic Steel Fe–17Mn–6Si–0.3C with High Silicon and High Manganese

引用

Acta Metallurgica Sinica(English Letters) 2014年第2期27卷 352-358页

作者： Haitao Si Renlong Xiong Fan Song yuhua wen Huabei Peng School of Manufacturing Science and Engineering Sichuan University

To solve the problem of poor wear resistance in conventional Hadfield steels under medium and low stress, a new kind of steel with high silicon and high manganese Fe-17Mn-6Si-0.3C was designed and its wear resistance was studied. The results showed that it exhibited better wear resistance than conventional Hadfield steel in both dry friction and abrasive friction. The better wear resistance of the new steel with high silicon and high manganese resulted from the stressinduced γ→ε martensitic transformation.

关键词： High manganese steel Fe-Mn based alloys Wear resistance Martensitic transformation

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

Effect of cyclic heat treatment on abnormal grain growth in Fe-Mn-Al-based shape memory alloys with different Ni contents

引用

Journal of Materials Science & Technology 2023年第22期153卷 8-21页

作者： Huabei Peng Liqiu Yong Yang Zuo Jiazhen Yan Hui Wang yuhua wen School of Mechanical Engineering Sichuan UniversityChengdu 610065China Key Laboratory of Radiation Physics and Technology of Ministry of Education Institute of Nuclear Science and TechnologySichuan UniversityChengdu 610064China Interdisciplinary Materials Research Center Institute for Advanced StudyChengdu UniversityChengdu 610106China

Cyclic heat treatment that can continuously promote abnormal grain growth is widely used for the prepa-ration of single-crystal Fe-Mn-Al-based shape memory ***,it takes a long time to prepare large-size Fe-Mn-Al-based alloy single crystals via the reported cyclic heat ***,the long-time cyclic heat treatment at high temperatures leads to the development of defects including oxidation and a decrease in Mn,which would deteriorate superelasticity in the Fe-Mn-Al-based shape memory *** shorten the fabrication time of single crystals,the effect of the cyclic heat treatment process on the abnormal grain growth in the Fe-Mn-Al-based alloys with different Ni contents was systematically *** is found that the abnormal grain growth of Fe-Mn-Al-based alloys was not significantly affected by the Ni contents(within 2.1 at.%-6.2 at.%).In addition,the abnormal grain growth could be promoted by 1-2℃ min^(-1) cooling rate,high solution temperature,and multiple cycles,while it was insensitive to other processes including heating rate,dual-phase time as well as long-time solution *** findings can guide optimizing the fabrication process of single crystals by cyclic heat ***,the Fe_(41.9)Mn_(37.8)Al_(14.1) Ni_(6.2) single crystal prepared by the optimized cyclic heat treatment showed a recoverable strain of about 4%.

关键词： Cyclic heat treatment Ni content Abnormal grain growth Fe-Mn-Al-based shape memory alloy Superelasticity

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

Shape Memory Effect of As-aged Fe-14Mn-5Si-8Cr-4Ni-0.2C Alloy

引用

Journal of Materials Science & Technology 2000年第4期16卷 424-426页

作者： yuhua wen, Ning LI and Mingjing TU (Department of Materials Shaping and Controlling Engineering, Sichuan University, Chengdu 610065, China) Department of Materials Shaping and Controlling Engineering Sichuan University Chengdu 610065 China

The effects of aging temperature on shape memory effect, mechanical properties and microstruc-ture of Fe-14Mn-5Si-8Cr-4Ni-0.2C shape memory alloy have been studied. The results showed that the second phase particles rich in chromium, manganese and silicon precipitate during aging, and thereby increase the hardness and strength of the alloy. The shape recovery ratio can be remarkably improved by aging and a maximum value can be obtained at 1223 K, which is 68% higher than that of the specimen in solid solution state. When the aging temperature is below 1223 K, the amount of second phase particles increases as the aging temperature increases. The size of austenite grain increases with increasing aging temperature. When the temperature is over 1223 K, the second phase particles can not precipitate. The lack of second phase particles and the increase of grain size make the hardness and shape recovery ratio drastically decrease, when the temperature is over 1223 K.

关键词： Mn Shape Memory Effect of As-aged Fe-14Mn-5Si-8Cr-4Ni-0.2C Alloy As Fe Cr Ni Si

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

Deformation-induced interfacial-twin-boundary ω-phase in an Fe_(48)Mn_(37)Al_(15) body-centered cubic metastable alloy

引用

Journal of Materials Science & Technology 2023年第15期146卷 252-258页

作者： Huabei Peng Xiao Yang Lixin Sun Liqiu Yong Jiazhen Yan Jinyong Zhang Bingnan Qian yuhua wen School of Mechanical Engineering Sichuan UniversityChengdu 610065China School of Mechanical Engineering Hebei University of TechnologyTianjin 300401China State Key Laboratory of Materials Processing and Die and Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China School of Materials and Physics China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Innovation Center NPU ChongqingChongqing 401135China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055China

Omega(ω)phase has a trigonal or hexagonal crystal structure and was first discovered inβ-type Ti-Cr alloys[1].Since then,theω-phase has been widely reported in numerous group IV transition metal(Ti,Ta,Hf,and Zr)based alloys[2–9].The morphologies ofω-phase could be particle-like(athermalω-phase)[10],ellipsoidal or cuboidal after aging(isothermalω-phase)[11],and plate-like after deformation(stress-relatedω-phase)[12].Amongst,the stressrelatedω-phase is usually located at the twinning boundary,thus also called interfacial-twin-boundary-ω(ITB-ω)*** formation of the ITB-ωphase is considered to be related to the formation of{112}bccmechanical twin(i.e.,{112}bcc twin)in bodycentered cubic(BCC)metals and alloys[13].

关键词： alloys alloy deformation

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

Factors Affecting Transformation Temperatures in Fe-Mn-Si-Cr-Ni Shape Memory Alloy

引用

Journal of Materials Science & Technology 2000年第5期16卷 537-539页

作者： yuhua wen+, ding LI and Mingjing TU (Department of Materials Shaping and Controlling Engineering, Sichuan University, Chengdu 610065, China) Department of Materials Shaping and Controlling Engineering Sichuan University Chengdu 610065 China

The effects of prestrain and annealing temperature on phase transformation temperatures in Fel4Mn5Si8Cr4Ni shape memory alloy have been studied. The results showed that when the annealing temperature was 673 K, both the At and the Ms temperatures increased appreciably as the prestrain increased, the As temperature increased slightly with increasing prestrain; the resistivity difference at 303 K between the heating and cooling curve also increased with increasing prestrain, which agreed with the recovery strain. The shape memory effect in Fe-Mn-Si-Cr-Ni shape memory alloy is caused by the stress-induced γ→ε martensite transformation and its reverse transformation. When the prestrain was 10%, the Ms temperature decreased remarkably as the annealing temperature increased.

关键词： Factors Affecting Transformation Temperatures in Fe-Mn-Si-Cr-Ni Shape Memory Alloy Fe Mn Cr Ni Si

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

基于修正IPA方法的温泉游客满意度研究——以甘肃温泉旅游景区为例

引用

干旱区资源与环境 2018年第5期32卷 196-201页

作者：温煜华中共甘肃省委党校经济社会发展研究所兰州730070

游客满意度研究是提升旅游目的地竞争力的重要依据。文中以甘肃温泉旅游景区为例,运用修正的IPA方法对甘肃温泉旅游景区作了实证研究。结果表明:游客对甘肃温泉旅游地的满意度为基本满意。配对样本t检验显示影响温泉游客满意度的23项因... 详细信息

游客满意度研究是提升旅游目的地竞争力的重要依据。文中以甘肃温泉旅游景区为例,运用修正的IPA方法对甘肃温泉旅游景区作了实证研究。结果表明:游客对甘肃温泉旅游地的满意度为基本满意。配对样本t检验显示影响温泉游客满意度的23项因子中,有19项因子的重要性和实际绩效之间存在显著性差异。将23项因子定位到修正IPA图中的4个象限,分析甘肃温泉旅游业发展中的优劣势,提出4种发展策略分别是"继续保持"、"过度努力"、"低优先"、和"集中关注",修正的IPA法能清晰地指出各项因子改进的轻重缓急之势。当务之急,甘肃温泉旅游景区应将更多的精力集中在"集中关注"区中的13项因子上,并针对性地提出了拓展温泉旅游产品体系、加强旅游基础设施建设、施行人性化的旅游管理与服务等策略来提高温泉旅游景区的竞争力。

关键词：温泉旅游游客满意度修正的IPA方法甘肃

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：