检索结果-南通市图书馆

High-Speed Friction Stir Welding of T6-Treated B4Cp/6061Al Composite

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2020年第1期33卷 67-74页

作者： y.Z.Li y.n.Zan Q.Z.Wang B.L.xiao Z.y.ma Key Laboratory of nuclear materials and Safety Assessment Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China Sheny.ng national Laboratory for materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China University of Science and Technology of China Shenyang 110016China

T6-treated 20 wt% B4 Cp/6061 Al sheets were joined under welding speeds of 400–1200 mm/min by friction stir welding(FSW) with a threaded cermet pin. The macro-defect-free FSW joints could be achieved at high welding speeds up to 1200 mm/min, but larger plunge depth was required at the welding speeds of 800 and 1200 mm/min to eliminate the tunnel defect. In the nugget zone(nZ) of the joints, the B4 C particles were broken up and uniformly redistributed. The nZ exhibited lower hardness than the base metal(BM), and the hardness value almost did not change with increasing welding speed, attributable to the dissolution of precipitates. Compared with the BM, the joints showed lower tensile strength. As the welding speed increased from 400 to 800 mm/min, the joint efficiencies were nearly the same and up to ~ 73%. When the welding speed increased up to 1200 mm/min, the tensile strength significantly decreased, due to the occurrence of kissing bond defect at the bottom of the nZ. With increasing welding speed, the fracture location of the joints transferred gradually from the heat-affected zone to the nZ due to the kissing bond defects.

关键词： Metal-matrix composites Microstructures Mechanical properties Friction stir welding High-speed welding

Achieving Large-area Bulk Ultrafine Grained Cu via Submerged Multiple-pass Friction Stir Processing

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2013年第12期29卷 1111-1115页

作者： P. Xue B.L. xiao Z.y. ma Sheny.ng national Laboratory for materials Science Institute of Metal Research Chinese Academy of Sciences 72 Wenhua Road Shenyang 110016 China

Large-area bulk ultrafine grained （UFG） pure Cu was successfully prepared by multiple-pass overlapping friction stir processing （FSP） under additional rapid cooling. Overlapping FSP did not exert a significant effect on the microstructure and mechanical properties of the FSP UFG Cu. Similar average grain size was achieved in the transitional zone （TZ） of the multiple-pass FSP sample compared to that in the nugget zone of the single-pass FSP sample, and the TZ exhibited a strong {111}（112） type A fiber shear texture, Very weak softening occurred in the TZ of the multiple-pass FSP UFG Cu, resulting in a relatively uniform hardness distribution throughout the whole processed zone. A high yield strength of - 310 MPa and a uniform elongation of - 13% were achieved in the bulk FSP UFG Cu. This study provides an effective strategy to prepare large-area bulk IUFG materials.

关键词： Friction stir processing Multiple-pass Ultrafine grains Microstructure Mechanical properties

Effect of Al_(2)O_(3)on the Mechanical Properties of(B_(4)C+Al_(2)O_(3))/Al neutron Absorbing materials

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1411-1420页

作者： J.X.Cai B.M.Shi n.Li y.Liu Z.G.Zhang y.n.Zan Q.Z.Wang B.L.xiao Z.y.ma Shi‑Changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Laboratory of nuclear materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China nuclear Equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.Ltd.Beijing 100840China Department of materials Science School of Mechanical EngineeringShenyang UniversityShenyang 110044China

B_(4)C/Al composites are widely utilized as neutron absorbing materials for the storage and transportation of spent nuclear *** order to improve the high-temperature mechanical properties of B_(4)C/Al composites,in-situ nano-Al_(2)O_(3)was introduced utilizing oxide on Al powder *** this study,the Al_(2)O_(3)content was adjusted by utilizing spheroid Al powder with vary.ng diameters,thereby investigating the impact of Al_(2)O_(3)content on the tensile properties of(B_(4)C+Al_(2)O_(3))/Al *** was found that the pinning effect of Al_(2)O_(3)on the grain boundaries could hinder the recovery of dislocations and lead to dislocation accumulation at high *** the result,with the increase in Al_(2)O_(3)content and the decrease in grain size,the high-temperature strength of the composites increased *** finest Al powder used in this investigation had a diameter of 1.4μm,whereas the resultant composite exhibited a maximum strength of 251 MPa at room temperature and 133 MPa at 350℃,surpassing that of traditional B_(4)C/Al composites.

关键词： Al matrix composites neutron absorbing materials (B_(4)C+Al_(2)O_(3))/Al composites High-temperature strength

Microstructure evolution and hot deformation behavior of carbon nanotube reinforced 2009Al composite with bimodal grain structure

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 2021年第11期70卷 73-82页

作者： K.ma Z.y.Liu S.Bi X.X.Zhang B.L.xiao Z.y.ma Shi-changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of ScienceShenyang110016China School of materials Science and Engineering University of Science and Technology of China72 Wenhua RoadShenyang110016China School of materials Science and Engineering Guilin University of TechnologyGuilin541004China

The hot deformation behaviors of the bimodal carbon nanotube reinforced 2009Al(CnT/2009Al)composite were studied by establishing processing map and characterizing the microstructure *** results indicate that the grain size in the ultra-fine grained zones was stable during hot deformation,while the coarse grained zones were elongated with their long axis directions tending to be perpendicular to the compression *** temperature with high strain rate(LTHR),as well as high temperature with low strain rate(HTLR)could increase the length/width ratio of the coarse grained ***,LTHR and HTLR could cause the instable *** instable deformation at LTHR was induced by severe intragranular plastic deformation and the localized shear crack,while the instable deformation at HTLR resulted from the more deformation component at the coarse grained zones,and the micro-pore initiation due to CnT re-agglomeration at the boundaries between the coarse and the ultra-fine grained zones.

关键词： Carbon nanotube Bimodal Aluminum matrix composite Hot deformation Processing map

Effect of Carbon nanotube Orientation on Mechanical Properties and Thermal Expansion Coefficient of Carbon nanotube-Reinforced Aluminum matrix Composites

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2014年第5期27卷 901-908页

作者： Z.y.Liu B.L.xiao W.G.Wang Z.y.ma School of materials Science and Engineering Dalian University of Technology Sheny.ng national Laboratory for materials Science Institute of Metal ResearchChinese Academy of Sciences School of Mechanical Engineering Liaoning Shihua University

Carbon nanotube-reinforced 2009Al （CnT/2009Al） composites with randomly oriented CnTs and aligned CnTs were fabricated by friction stir processing （FSP） and FSP-rolling, respectively. The CnT/2009A1 composites with aligned CnTs showed much better tensile properties at room temperature and elevated temperature compared with those with the randomly oriented CnTs, which is mainly attributed to larger equivalent aspect ratio of the CnTs and avoidance of preferential fracture problems. However, much finer grain size was not beneficial to obtaining high strength above 473 K. The aligned CnTs resulted in tensile anisotropy, with the best tensile properties being achieved along the direction of CnT aligning. As the off-axis angle increased, the tensile properties were reduced due to the weakening of the load transfer ability. Furthermore, aligned CnTs resulted in much lower coefficient of thermal expansion compared with randomly oriented CnTs.

关键词： Carbon nanotubes Metal matrix composites Mechanical properties Coefficient of thermalexpansion Friction stir processing

Tensile Strength and Electrical Conductivity of Carbon nanotube Reinforced Aluminum matrix Composites Fabricated by Powder Metallurgy Combined with Friction Stir Processing

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7期30卷 649-655页

作者： Z.y.Liu B.L.xiao W.G.Wang Z.y.ma Sheny.ng national Laboratory for materials Science Institute of Metal ResearchChinese Academy of Sciences Dalian University of Technology Liaoning Shihua University

A route combining powder metallurgy and subsequent friction stir processing was utilized to fabricate carbon nanotube （CnT） reinforced AI （CnT/AI） and 6061AI （CnT/6061AI） composites. Microstructural observations indicated that CnTs were uniformly dispersed in the matrix in both CnT/AI and CnT/6061AI composites. Mg and Si elements tended to segregate at CnT-AI interfaces in the CnT/6061AI composite during artificial aging treatment. The tensile properties of both the AI and 6061AI were increased by CnT incorporation. The electrical conductivity of CnT/AI was decreased by CnT addition, while CnT/6061AI exhibited an increase in electrical conductivity due to the Mg and Si segregation.

关键词： Carbon nanotubes Metal matrix composites Mechanical properties Electrical properties Friction stir processing

Water mass characteristics in the western north Pacific based on a streamfunction projection

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2015年第11期58卷 2067-2077页

作者： ma xiao SUn Che Institute of Oceanology Chinese Academy of Sciences College of Earth Sciences University of Chinese Academy of Sciences

A streamfunction projection method called gravest empirical mode(GEM) is applied to the hydrographic section at 137°E to filter out eddy.noises in the western north Pacific and derive quantitative ensemble-average water mass properties in the north Equatorial Current region. The GEM fields capture more than 80% of total property variances in the thermocline layer. The core layer structures of key water masses, including the north Pacific Tropical Water(nPTW) and the north Pacific Intermediate Water(nPIW), are examined with a definition of water mass boundary based on property gradient. It shows that a tongue of maximal root-mean-square(RMS) residual exists in the upper half of nPIW for all water properties. These subsurface RMS tongues appear to be close to sharp property gradients. It is the first time a GEM diagnosis is applied to nutrient data, which reveals a drastic difference of n/P reaction rate ratio above and below the maximal-nutrient core at 1250 m. Additionally, a GEM velocity reconstruction successfully produces the north Equatorial Undercurrent(nEUC), demonstrating the stable thermal-wind nature of this newly-discovered current.

关键词： streamfunction projection gravest empirical mode water masses western north Pacific

Superb Strengthening Effect of net-Like Distributed Amorphous Al_(2)O_(3)on Creep Resistance of(B_(4)C+Al_(2)O_(3))/Al neutron-Absorbing materials

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12期35卷 2007-2013页

作者： y.n.Zan X.Lei J.F.Zhang D.Wang Q.Z.Wang B.L.xiao Z.y.ma Key Laboratory of nuclear materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Shi-Changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China nuclear Equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.LtdBejing 100840China

B4C reinforced Al composites are widely used as neutron absorbing materials(nAMs)due to excellent neutron absorbing efficiency,however,such nAMs exhibit poor high-temperature *** meet the requirement for structure-function integration,nAMs with enhanced high-temperature mechanical properties are *** this work,a novel(B4 C+Al_(2)O_(3))/Al nAM with netlike distribution of Al_(2)O_(3)was fabricated by powder metallurgy method and subjected to high-temperature tensile creep *** was shown that the creep resistance was enhanced by several orders of magnitude via the addition of only2.1 vol.%netlike-distributed Al_(2)O_(3).(B_(4)C+Al_(2)O_(3))/Al exhibited high apparent stress exponents ranging from 16 to 25 and high apparent activation energy of 364 kJ/*** creep behaviour could be rationalized using the substructure-invariant model and its rupture behaviour could be described by the Dobes-Milicka equation.

关键词： neutron absorber material Al matrix composite Tensile creep B_(4)C/Al

Efect of nanometer WC Coating on Thermal Conductivity of Diamond/6061 Composites

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2023年第1期36卷 118-126页

作者： Z.y.Dong D.Wang W.G.Wang B.L.xiao Z.y.ma Shi-changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Liaoning Shihua University Fushun 113001China

Diamond has poor interface tolerance with *** enhance interface bonding,in this study,tungsten carbide(WC)nanocoatings on the surface of diamond particles were prepared using sol–gel and in-situ reaction ***_(3) sol–gel with two concentrations,0.2 mol/L,and 0.5 mol/L,was,respectively,coated on diamond particles,then sintered at 1250℃for 2 h to produce WC *** concentration of 0.2 mol/L WO_(3) sol–gel was not enough to cover the surface of the diamond completely,while 0.5 mol/L WO_(3) sol–gel could fully cover ***,WO_(3) was preferentially deposited on{100}planes of the ***_(3) converted to WC in-situ nanocoatings after sintering due to the in-situ reaction of WO_(3) and *** diamond-reinforced Al composites with and without WC coating were fabricated by powder *** diamond/Al composite without coating has a thermal conductivity of 584.7 W/mK,while the composite with a coating formed by 0.2 mol/L and 0.5 mol/L WO_(3) sol–gel showed thermal conductivities of 626.1 W/mK and 584.2 W/mK,*** moderate thickness of nanocoatings formed by 0.2 mol/L WO_(3) sol–gel could enhance interface bonding,therefore improving thermal *** nanocoating produced by 0.5 mol/L WO_(3) sol–gel cracked during the fabrication of the composite,leading to Al12W formation and a decrease in thermal conductivity.

关键词： Diamond Al matrix composite nanometer coating WC Thermal conductivity