检索结果-南通市图书馆

Microstructure and mechanical property of Mg-10Gd-2Y-1.5Zn-0.5Zr alloy processed by eight-pass equal-channel angular pressing

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2023年第4期42卷 1371-1377页

作者： Huan Liu Jia Ju Xiao-Wei Yang Yu-Hua Li Jing-Hua Jiang Ai-Bin Ma College of Mechanics and Materials Hohai UniversityNanjing211100China Suqian Research Institute of Hohai University Suqian223800China College of Materials Engineering Nanjing Institute of TechnologyNanjing211167China

In this work,a high-strength Mg-10Gd-2Y-1.5Zn-0.5Zr(wt%)alloy was prepared via eight passes of equal-channel angular pressing(ECAP).The microstructures and mechanical properties of as-cast and ECAP alloys were systematically investigated by X-ray diffraction(XRD),optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and electronic universal testing *** obtained results indicate that the microstructure of as-cast alloy consists ofα-Mg dendrite,network Mg3(Gd,Y,Zn)phase and lamellar 14H long-period stacking ordered(LPSO)phase which is precipitated near the boundary of Mg3(Gd,Y,Zn)*** eight-pass ECAP,the network Mg3(Gd,Y,Zn)phase is deformed and ***,the refined Mg_3(Gd,Y,Zn)particles are not distributed uniformly in the matrix,but still aggregated at the interdendritic ***,the content of 14H lamellas increases obviously,and they become bent and kinked during severe *** is activated in the region between Mg3(Gd,Y,Zn)particles and 14H *** test at room temperature indicates that the ECAP alloy exhibits excellent mechanical property with compressive strength of 518 MPa and fracture strain of 21.6%.The comprehensive high strength and toughness could be ascribed to the refined Mg_3(Gd,Y,Zn)particles,DRX grains and kinked 14H LPSO phase.

关键词： Mg-Gd-Y-Zn-Zr Long-period stacking ordered phase equal-channel angular pressing Compression strength Fracture strain

Microstructure and tensile properties of ultrafine grained copper processed by equal-channel angular pressing

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2006年第6期25卷 697-703页

作者： WEI Wei CHEN Guang WANG Jingtao CHEN Guoliang Department of Materials Science and Engineering Jiangsu Polytechnic University Changzhou 213016 China Department of Materials Science and Engineering Nanjing University of Science and Technology Nanjing 210094 China

equal-channel angular pressing （ECAP） process was applied to a 12 mm ×12 mm ×80 mm billet of pure copper （99.98 wt.%） at room temperature. The shear deformation characteristics, microstructure evolution, and tensile properties were investigated. A combination of high strength （-420 MPa） and high elongation to failure （-25%） was achieved after eight ECAP passes at room temperature. The mixing of ultrafme grains （-0.2 μm） with nanocrystalline grains （-80 nm） resulted in high tensile strength and ductility.

关键词： equal-channel angular pressing copper microstructure tensile properties ultrafine grain size

Microstructural evolution and fracture mechanism of a new AlZn-Mg-Cu-Zr alloy processed by equal-channel angular pressing

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2022年第10期41卷 3546-3551页

作者： Hong-Li Liu Ping Li Ke-Min Xue Chen-Hao Qian Rui Hua School of Materials Science and Engineering Hefei University of TechnologyHefei230009China

equal-channel angular pressing(ECAP) is considered to be one of the most effective processing procedures to produce ultrafine-grained(UFG) materials.A new AI-ZnMg-Cu-Zr alloy was subjected to ECAP experiment in Route B_(C)(i.e.,rotated 90° in the same sense between each pass).The effect of ECAP on the microstructural evolution and fracture mechanism of the alloy was analyzed by optical microscope(OM),X-ray diffraction(XRD),tensile test(at room temperature),and scanning electron microscope(SEM).The results show that the main strengthening phase of the alloy is MgZn_(2),whose content increases apparently after ECAP,the dislocation density increases by one order of magnitude,the hardness value of the 1 pass ECAPed sample increases by 53 %,the ultimate tensile strength(UTS)increases by 29 %,and the true strain increases by 15.4 %.But the further increase in the strength with the passes increasing would cost a slight drop in the true *** morphology of the tensile dimples is converted from elongated one to equiaxed one with a uniform distribution of size and depth after pressing.

关键词： Al-Zn-Mg-Cu-Zr alloy equal-channel angular pressing Microstructural evolution Crystallite size Mechanical properties Fracture mechanism

Achieving High Strength and High Electrical Conductivity in a CuCrZr Alloy Using equal-channel angular pressing

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2018年第10期31卷 1084-1088页

作者： Yun-Xiang Tong Yu Wang Zhi-Min Qian Dian-Tao Zhang Li Li Yu-Feng Zheng Institute of Materials Processing and Intelligent Manufacturing College of Materials Science and Chemical Engineering Harbin Engineering University Department of Materials Science and Engineering College of Engineering Peking University

In the present work, a CuCrZr alloy characterized by ultrafine grains and nanoscale particles was prepared by equalchannel angular pressing （ECAP） at 450℃. A desired combination of a tensile strength （580 MPa） and an electrical conductivity （81% International Annealed Copper Standard） is simultaneously obtained in the as-ECAP-processed CuCrZr alloy without additional aging treatment. The improved properties can be mainly attributed to the ultrafine grains and nanoscale precipitates. This processing may pave a way to develop the CuCrZr alloys having high strength and high electrical conductivity for engineering applications.

关键词： Microstructure CuCrZr equal-channel angular pressing Strengthening

The Stamping Formability of AZ31 Magnesium Alloy Sheet Improved by equal-channel angular pressing

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2010年第2期25卷 234-237页

作者：刘英 Department of Material Science and Engineering Jinan University

equal channel angular pressing （ECAP） processing and annealing were applied to the AZ31 magnesium alloy sheets to evaluate the potential improvement in the mechanical properties and formability. The ECAP experiment was conducted at 300 ℃ in a die having an included angle of 90o between two channels by the BCZ route with the sheets rotated by 90°about the normal axis of plate plane. The tensile tests and conical cup tests were conducted at various temperatures from 20 to 250 ℃. The experimental results indicated that improving the working temperatures could lead to the soft in the material and the enhancement of ductility. Comparatively, the ECAPed AZ31 alloy sheets showed the lower yield strength and smaller conical cup value （CCV） than the unECAPed counterpart in the room temperature. The difference in yield strength between them became small in the elevated temperature, but the ECAPed samples still had the smaller CCV value, implying the improved formability. The texture of the AZ31 alloy sheets could be modified by ECAP and the decrease in the yield strength and more uniform deformation realized in the material, so the formability of AZ31 alloy sheets was improved.

关键词： AZ31 magnesium alloy sheets equal-channel angular pressing mechanical properties conical cup value (CCV)

Microstructure and Mechanical Properties of Ultrafine Grained Mg15Al Alloy Processed by equal-channel angular pressing

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2010年第2期25卷 238-242页

作者：王红霞梁伟 College of Materials Science and Engineering Taiyuan University of Technology Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education Taiyuan University of Technology

An as-cast magnesium alloy with high Al content Mg15Al was subjected to equal-channel angular pressing （ECAP） through a die with an angle of φ= 90？ at 553 K following route Bc. It is found that the network β-Mg17Al12 phases in the as-cast Mg15Al alloy are broken into small blocks and dispersed uniformly with increasing numbers of pressing passes. Moreover, many nano-sized Mg17Al12 particles precipitate in the ultra-fine α-Mg matrix. The grains are obviously refined. However, the grain structure is inhomogeneous in different areas of the alloy. The average size of the primary phase α-Mg is reduced to about 1 μm while grains of around 0.1-0.2 μm are obtained in some two-phase areas. With additional ECAP passes （up to 8）, coarsening of the grains occurs by dynamic recovery. Room temperature tensile tests show that the mechanical properties of Mg15Al alloys are markedly improved after 4 ECAP passes. The ultimate tensile strength and elongation to failure increase from 150 MPa to 269.3 MPa and from 0.05% to 7.4%, respectively. Compared with that after 4 passes, the elongation to failure of the alloy increases but the strength of the alloy slightly decreases after 8 ECAP passes. Fracture morphology of the ECAP-processed alloy exhibits dimple-like fracture characteristics while the as-cast alloy shows quasi-cleavage fractures.

关键词： high-aluminum Mg Alloy β-Mg17Al12 phase ultra-fine grained microstructure mechanical properties equal-channel angular pressing

Improvement of pitting corrosion resistance for Al-Cu alloy in sodium chloride solution through equal-channel angular pressing

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2011年第4期21卷 307-313页

作者： Dan SONG,Ai-bin MA,Jing-hua JIANG,Ping-hua LIN,Liu-yan ZHANG College of Mechanics and Materials,Hohai University,Nanjing 210098,China College of Mechanics and Materials Hohai University Nanjing 210098 China

Significant corrosion resistance improvement was achieved in solid-solution treated(T4) Al-Cu alloy after severe grain refinement through equal-channel angular *** bulk ultrafine-grained Al-Cu alloy with grain sizes of 200-300 nm has higher pitting potential(elevated by about 34 mV,SCE) and lower corrosion current density(decreased by about 3.88μA/cm~2) in polarization tests than the as-T4 alloy,and increased polarization resistance(increased by about 5.7 kΩ·cm~2) in electrochemical impendence spectrum tests,along with alleviated corrosion damage in immersion *** factors responds to the improved corrosion resistance of the alloy:the first is the refinement of residualθ-phase(Al2Cu) particles leading to the lower micro-galvanic currents and reduced susceptibilities to pitting corrosion,the second is the mass of strain-induced crystalline defects providing more nucleation sites for the formation of more volume fractions of stable oxide film.

关键词： Al-Cu alloy equal-channel angular pressing pitting corrosion resistance ultrafine-grained particle

Effect of equal-channel angular pressing and aging on corrosion behavior of ZK60 Mg alloy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2015年第12期25卷 3909-3920页

作者：李鑫江静华赵永好马爱斌文道静朱运田南京理工大学材料科学与工程学院南京210094 河海大学力学与材料学院南京210098 Department of Materials Science and Engineering NC State University

Commercial ZK60 Mg alloy was processed by multi-pass equal-channel angular pressing（ECAP） and subsequent aging to investigate the effect of grain refinement and second-phase redistribution on its corrosion behavior. Electrochemical tests show that the fine-grained samples after more ECAP passes have higher corrosion current densities（Jcorr） in the polarization curves, lower charge-transfer resistance（Rt） values in the EIS plots. The severe plastic deformation decreases the alloy corrosion resistance besides the well-known strengthening and toughening. Scanning Kelvin probe（SKP） measurement shows that the anodic and cathode sites are homogeneously distributed on the surface of the fine-grained alloy, which inhibits localized corrosion. The SKP potential, having linear relationship with the corrosion potential（φcorr）, decreases with increasing the ECAP pass. Furthermore, the post-ECAP aging can slightly improve the corrosion resistance of the fine-grained ZK60 Mg alloy and enhance the comprehensive performances, due to the stress relief and uniform distribution of second-phase particles.

关键词： ZK60 Mg alloy equal-channel angular pressing aging corrosion resistance fine-grains

Influence of Processing Parameters on Microstructural Evolution and Tensile Properties for 7075 Al Alloy Prepared by an ECAP-Based SIMA Process

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2018年第4期31卷 337-350页

作者： Jin-Long Fu Hong-Jun Jiang Kai-Kun Wang School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Wuxi Turbine Blade Co. LtdWuxi 214174JiangsuChina

A modified strain-induced melt activation（SIMA）process consisting of homogenization,equal-channel angular pressing（ECAP）and subsequent heating to the semisolid temperatures was introduced to prepare the 7075 aluminum alloy with superior thixotropic *** effects of both the homogenization and the number of ECAP passes,as well as the isothermal temperatures on the microstructural evolution,were *** results indicate that ideal microstructure wherein fine and globular solid grains surrounded by uniform liquid films can be achieved through ECAP deformation-recrystallization *** the number of ECAP passes accelerates the recrystallization of strained grains,thus reducing the average grain size and improving the grain ***,higher holding temperatures and prolonged soaking time can improve the growth of the solid *** main coarsening mechanisms,*** and Ostwald ripening,contribute to the growth of the solid grains simultaneously and *** tensile strength of the 7075 alloys after four-pass ECAP-based SIMA and T6 heat treatment is relatively lower than the as-received billet,while the elongation of SIMA processed samples is much higher than that of as-received *** the number of ECAP passes improves the tensile strength for alloys with and without T6 treatment due to the fine grain strengthening mechanism.

关键词： Semisolid Aluminum equal-channel angular pressing Mierostructural evolution Tensileproperty