检索结果-南通市图书馆

Tension-compression asymmetry and corresponding deformation mechanism in ZA21 magnesium bars with bimodal structure

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2023年第1期30卷 92-103页

作者： Yujiao Wang Yun Zhang haitao jiang Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China Beijing Institute of Machinery and Equipment Beijing 100854China

We investigated the asymmetric tension-compression(T-C)behavior of ZA21 bars with bimodal and uniform structures through axial tension and compression *** results show that the yield strengths of bars having bimodal structure are 206.42 and 140.28 MPa under tension and compression,respectively,which are higher than those of bars having uniform structure with tensile and compressive yield strength of 183.71 and 102.86 MPa,*** slip and extension twinning under tension and basal slip and extension twinning under compression dominate the yield behavior and induce the T-C ***,due to the basal slip activated in fine grains under tension and the inhibition of extension twinning by fine grains under compression,the bimodal structure possesses a lower T-C asymmetry(0.68)compared to the uniform structure(0.56).Multiple extension twins occur during deformation,and the selection of twin variants depends on the Schmid factor of the six variants activated by parent ***,the strengthening effect of the bimodal structure depends on the grain size and the ratio of coarse and fine grains.

关键词： bimodal structure deformation mechanism Hall-Petch relationship tension-compression asymmetry twin variant selection

Texture and Microstructure Evolution During Tensile Testing of TWIP Steels with Diverse Stacking Fault Energy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2013年第6期26卷 713-720页

作者： Yanxin WU Di TANG haitao jiang Zhenli MI haitao JING National Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing SAIC Motor Passenger Vehicle Co Shanghai

Texture and microstructure evolution in two kinds of the twinning induced plasticity （TWIP） steels （Fe-Mn- Si-AI and Fe-Mn-C） with diverse stacking fault energies during tensile testing were investigated by interrupted testing. The strain-hardening rate curves of the two steels were quite similar, but the texture characterization curves （maximum of pole density measured by X-ray diffraction） were varied. According to the curvature of max pole density curves, the evolution of the texture and the microstructure can be divided into three stages： low strain stage, medium stage and high stage. In low strain stage the difference of the microstructure came from the intensity of dislocation, which was much smaller in Fe-Mn-Si-AI. The main difference of the microstructure in medium and high strain stages originated from the numbers of activated twin systems. There were more than one twin systems activated in Fe-Mn-C, while only a single twin system activated in Fe-Mn-Si-AI. Texture showed various differences in the whole tensile process because it was affected by their micromechanism, such as concentration of the dislocation and the activation of twin systems. Texture in low strain stage was connected with annealing twin; the evolution ofthe texture was mainly induced by deformation twin generation. More than one activated twin systems in medium and high stages may counteract each other in the view of concentration of the grain orientations.

关键词： Work hardening rate Texture TWIP steel Stacking fault energy

Influence of isothermal bainitic processing on the mechanical properties and microstructure characterization of TRIP steel

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2008年第5期15卷 574-579页

作者： haitao jiang Hubin Wu Di Tang Qiang Liu National Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing Beijing 100083 China

The mechanical properties of transformation induced plasticity （TRIP） steel are strongly affected by the conditions of iso-thermal bainitic processing. The multiphase microstructure of TRIP steel under different conditions of isothermal bainitic processing was investigated using OM,SEM,XRD and TEM. The volume fraction of retained austenite and the carbon content in austenite were determined quantitatively using X-ray diffraction patterns. The relationship between mechanical properties and isothermal bainitic processing parameters was investigated. The stability of retained austenite was analyzed by the volume fraction of retained austenite and the carbon content in retained austenite. The experimental results show that the multiphase microstructure consists of ferrite,bainite and metastable retained *** obtain good mechanical properties,the optimal conditions of isothermal bainitic temperature and holding time are 410-430°C and 180-240 s,respectively. After isothermal bainitic processing under the optimal conditions,the corresponding volume fraction of retained austenite is 5vol%-15vol%,which can provide enough retained austenite and plastic stability for austenite with high carbon content.

关键词： transformation induced plasticity steel isothermal bainitic processing mechanical properties microstructure

Microstructure evolution of Al-4Cu-Mg alloy during semi-solid treatment

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2007年第2期14卷 151-156页

作者： haitao jiang Zhenli Mi Di Tang Miaoquan Li National Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering Northwestern Polytechnical University Xi＇an 710072 China

The microstructure of a cold-deformed Al-4Cu-Mg alloy during semi-solid treatment was investigated, which shows that grain detachment and grain spheroidization processes during the semi-solid treatment are very important to control the fabricated semi-solid microstructures. For the two different processes, the driving force comes from the external heat source and the reduction in total interfacial area, respectively. The evolution models of microstructure morphology in the two processes were presented based on microstructure observations. It can be found that these models are useful to provide a reasonable estimated critical time of the evolution of microstructure during the semi-solid treatment.

关键词： Al-4Cu-Mg alloy semi-solid microstructure morphology evolution model

Role of Microalloyed Y and Gd in Improving the Corrosion Resistance of Rolled Mg-3Al-1Zn Alloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2022年第6期35卷 941-947页

作者： Panpan Wang haitao jiang Yujiao Wang Yun Zhang Jingchao Tao Shanghai Key Laboratory of Materials Laser Processing and Modification and National Engineering Research Center of Light Alloy Net FormingSchool of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Institute of Engineering Technology University of Science and TechnologyBeijingBeijing 100083China

The corrosion performances of rolled AZ31 alloy with addition of Y and Gd were comparatively investigated. The corrosion rates of AZ31 alloy modified with Y and Gd were 3.3 and 3.7 mm/y immersing for 24 h in 3.5 wt% NaCl solution, respectively, which were much lower than that of AZ31 alloy(23.6 mm/y). The remarkable improvement in corrosion performance by adding Y or Gd was ascribed to preferentially form less noble Al_(2)Y or Al_(6)GdMn_(6) and more protective corrosion product layer, resulting in the reduction in H_(2) evolution rate and the enhancement of passivity.

关键词： AZ31 alloy Second phases Volta potential diff erence Y Gd

Magnesium-based biomaterials as emerging agents for bone repair and regeneration:from mechanism to application

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2021年第3期9卷 779-804页

作者： Hang Zhou Bing Liang haitao jiang Zhongliang Deng Kexiao Yu Department of Orthopedics The Second Affiliated Hospital of Chongqing Medical University76 Linjiang RoadYuzhong DistinctChongqing 400010PR China Department of Pathology College of Basic MedicineChongqing Medical University1 Yixueyuan RoadYuzhong DistinctChongqing 400016PR China Department of Orthopedics Chongqing Traditional Chinese Medicine HospitalNo.6 Panxi seventh Branch roadJiangbei DistrictChongqing 400021PR China Institute of Ultrasound Imaging of Chongqing Medical University The Second Affiliated Hospital of Chongqing Medical University76 Linjiang RoadYuzhong DistinctChongqing 400010PR China

Magnesium(Mg)is the fourth most abundant element in the human body and is important in terms of specific osteogenesis ***,we provide a comprehensive review of the use of magnesium-based biomaterials(MBs)in bone *** review the history of MBs and their excellent biocompatibility,biodegradability and osteopromotive properties,highlighting them as candidates for a new generation of biodegradable orthopedic *** particular,the results reported in the field-specific literature(280 articles)in recent decades are dissected with respect to the extensive variety of MBs for orthopedic applications,including Mg/Mg alloys,bioglasses,bioceramics,and polymer *** also summarize the osteogenic mechanism of MBs,including a detailed section on the physiological process,namely,the enhanced osteogenesis,promotion of osteoblast adhesion and motility,immunomodulation,and enhanced ***,the merits and limitations of current bone grafts and substitutes are *** objective of this review is to reveal the strong potential of MBs for their use as agents in bone repair and regeneration and to highlight issues that impede their clinical ***,the development and challenges of MBs for transplanted orthopedic materials are discussed.

关键词： Magnesium-based biomaterials Bone reconstruction Orthopedic applications Future perspectives Clinical transformation

Precipitation behaviors of X70 acicular ferrite pipeline steel

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2006年第6期13卷 523-527页

作者： Hao Yu Yi Sun Qixiang Chen haitao jiang Lihong Zhang Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China Jinan Iron ＆ Steel Group Co. Jinan 250101 China

The morphology, structure, and chemical composition of precipitates in the final microstructure of Nb-V-Ti microalloyed X70 acicular ferrite pipeline steel were investigated using transmission electron microscopy （TEM） and energy dispersive X-ray spectroscopy （EDS）. Precipitates observed by TEM can be classified into two groups. The large precipitates are complex compounds that comprise square-shaped TiN precipitate as core with fine Nb-containing precipitate nucleated on pre-existing TiN precipitate as caps on one or more faces at high temperature. In contrast, the fine and spherical Nb carbides and/or carbonitrides precipitate heterogeneously on dislocations and sub-boundaries at low temperature. From the analysis in terms of thermodynamics, EDS and chemical cornposition of the steel, NbC precipitation is considered to be the predominant precipitation behavior in the tested steel under the processing conditions of this research.

关键词： pipeline steel acicular ferrite microstructure carbonitride precipitation behavior thermodynamics

Achieving superior strength-ductility balance in novel heterogeneous lamella structures of Al-Zn-Mg-Cu alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第17期184卷 122-135页

作者： haitao jiang Hui Xing Zihan Xu Jing Feng Jiao Zhang Baode Sun Shanghai Key Lab of Advanced High-Temperature Materials and Precision Forming Shanghai Jiao Tong UniversityShanghai 200240China State Key Lab of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration Shanghai Jiao Tong UniversityShanghai 200240China

Heterogeneous structures(HS)materials have the potential to exhibit simultaneous improvement in strength and plasticity due to hetero-deformation-induced hardening(HDI)between multiple grain ***,achieving HS in aluminum alloy can be quite *** this study,7000 series alu-minum alloys are investigated by incorporating rare earth element Y to develop a dual-phase structure containing Al_(8)Cu_(4)Y and Al_(3)(Y,Zr)*** a heterogeneous lamella structure(HLS)is formed through the synergistic effect of Al_(8)Cu_(4)Y which includes dynamic recrystallization nucleation during deformation,and Al_(3)(Y,Zr)which hinders the growth of recrystallized grain by means of pinning dislocations and sub-grain *** such as precipitates and nanocrystals are incorporated during the fabri-cation of HS,allowing for precise control over the volume fraction of fine grains by adjusting the ratio of two-scale second *** Y content reaches 0.3%,the 7Y55-2/heterogeneous lamella structure(HLS)samples exhibit a fine grain volume fraction of 76.5 vol.%,a tensile strength of 695 MPa,and an elon-gation of 16.6%.The alloy contains a large number of dislocations that preferentially induce the growth ofη’phases along specific directions,thereby promoting their *** multi-coupling effect and composite strengthening mechanisms in the“heterostructure-dislocation-precipitate”microstructure contribute to the intrinsic excellent strength and plasticity of the *** study tackles the challenge of inverted strength and plasticity observed in Al-Zn-Mg-Cu-Zr alloys,offering novel insights that pave the way for further applications of heterogeneous materials.

关键词： Al-Zn-Mg-Cu-Zr-Y alloy Heterogeneous lamella structures Properties HDI hardening Deformation mechanism

Design and Analysis of Microstrip Multi-Channeled Filter Using Photonic Crystal Branchy Defect

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 Rare Earths 2006年第Z1期24卷 136-139页

作者： Li Yunhui jiang haitao He Li Li Hongqiang Zhang Yewen Chen Hong Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China

A multi-channeled filter based on branchy defect in a microstrip photonic crystal was proposed. By introducing a branchy structure across the defect region, multiple defect modes will appear inside the photonic gap, leading to the multi-channeled filtering phenomenon. In comparison with the conventional multi-channeled filters, the proposed structure is more compact and tunable as far as the device volume and fabrication are concerned. The microwave experiment results are found in agreement with simulation results.

关键词： photonic crystals defect mode multi-channeled filter