检索结果-南通市图书馆

Ordering of the α-Fe(Si) Crystallization Phase in Annealed Fe_(73.5)Cu_1Mo_3Si_(13.5)B_9 Alloy

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 1997年第1期13卷 37-40页

作者： Jianhua LIU Xiangyi ZHANG and Yangzeng ZHENG (Dept. of materials engineering, yanshan university, qinhuangdao 066004, china)Jinhua ZHAO and Riping LIU (institute of physics, Chinese Academy of Sciences , beijing 100080, china)(Present address: institute Dept. of materials engineering Yanshan University Qinhuangdao 066004 China institute of physics Chinese Academy of Sciences Beijing 100080 China

The ordering of the α-Fe(Si) crystallization phase in annealed Fe73.5Cu1Mo3Si13.5B9 alloy has been studied using XRD method. The α-Fe(Si) phase in Fe73.5Cu1Mo3Si13.5B9 alloy annealed at 460℃ for 1 h consists of the DO3-type ordered region with spherical shape and disordered region. The size of DO3 ordered region increases with the annealing temperature. When the annealing temperature is 560℃, the size of the ordered region in the α-Fe(Si) grain is 14.0nm,which is nearly as large as that of the α-Fe(Si) grain (14.2 nm) and the degree of order of the α-Fe(Si) phase is about 0.78. When Fe73.5Cu1 Mo3Si13.5B9 amorphous alloy is annealed at 520℃， with the increment of the annealing time, the shape of the DO3 ordered region in the α-Fe(Si) phase is spheroidal at the beginning of the annealing and becomes spherical and has asize of 12.8 nm when the annealing time is 60 min. In addition, the DO3 superlattice lines of the α-Fe(Si) phase will vanish if Fe73.5Cu1Mo3Si13.5 B9 amorphous alloy is annealed for 1 h at 750℃.

关键词： Crystallization Phase in Annealed Fe Cu1Mo3Si Ordering of the B9 Alloy Si Mo

Magnetron sputtering synthesis of large area well-ordered boron nanowire arrays

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2004年第4期47卷 403-415页

作者： CAO Limin1,2, ZHANG Ze2 & WANG Wenkui1,2 1. Key Laboratory of Metastable materials Science and Technology and College of materials Science and engineering, yanshan university, qinhuangdao 066004, china 2. institute of physics, Chinese Academy of Sciences, beijing 100080, china 1. Key Laboratory of Metastable materials Science and Technology and College of materials Science and engineering Yanshan University 066004 Qinhuangdao China 2. institute of physics Chinese Academy of Sciences 100080 Beijing China

One-dimensionally nanostructured materials, such as nanowires and nanotubes, are the smallest dimensional structures for efficient transport of electrons and excitons, and are therefore critical building blocks for nanoscale electronic and mechanical devices. In this paper, boron nanowires with uniform diameters from 20 to 80 nm were synthesized by radio-frequency magnetron sputtering of pure boron powder and B2O3 powder mixtures in argon atmosphere. The boron nanowires produced stand vertically on the substrate surface to form well-ordered arrays over large areas with self- organized arrangements without involvement of any template and patterned catalyst. The high-density boron nanowires are parallel to each other and well distributed, forming highly ordered and uniform arrays. A more interesting and unique feature of the boron nanowires is that most of their tips are flat rather than hemispherical in morphologies. Detailed studies on its structure and composition indicate that boron nanowires are amorphous. Boron nanowire appears as a new member in the family of one-dimensional nanostructures. Considering the unique properties of boron-rich solids and other nanostructures, it is reasonable to expect that the boron nanowires will display some exceptional and interesting properties. A vapor-cluster-solid (VCS) mechanism was proposed to explain the growth of boron nanowires based on our experimental observations.

关键词： boron nanowires, magnetron sputtering, arrays, self-assembly.

SH-guided waves in layered piezoelectric/piezomagnetic plates

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:materials International 2009年第7期19卷 811-816页

作者： Guoquan Nie a,b, Zijun An a, Jinxi Liu b a College of Mechanical engineering, yanshan university, qinhuangdao 066004, china b department of engineering Mechanics, Shijiazhuang Railway institute, Shijiazhuang 050043, china [a]College of Mechanical engineering Yanshan University Qinhuangdao 066004 China [b]Department of Engineering Mechanics Shijiazhuang Railway Institute Shijiazhuang 050043 China

The propagation of shear horizontal (SH) guided waves in a coupled plate consisting of a piezoelectric layer and a piezomagnetic layer is studied. Both the layers are transversely isotropic and perfectly bonded along the interface. The upper and the lower surfaces of the plate are assumed to be mechanically free, electrically open and magnetically closed. Two different cases are considered. One is that the bulk shear wave velocity of piezoelectric material is larger than that of piezomagnetic material. The other is that the bulk shear wave velocity of piezomagnetic material is larger than that of piezoelectric material. The dispersion relation is obtained while the phase velocity is among the bulk shear wave velocity of two different layers. The numerical results show that the phase velocity approaches the smaller bulk shear wave velocity of the material in the system with the increase in the wave number for different modes. The thickness ratio and the properties of the piezoelectric material have great effect on the dispersion behaviors. The results of this paper can offer some fundamental theory to the application of piezoelectric/piezomagnetic composites or structures.

关键词： Piezoelectric material Piezomagnetic material SH-guided wave Dispersion relation

Effects of gravity on the microstructure of Zr_(41)Ti_(14)-Cu_(12.5)Ni_(10)Be_(22.5) bulk glass forming 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

Chinese Science Bulletin 2001年第11期46卷 961-963页

作者： LI Gong, ZHAN Zaiji, WANG Limin, CAO Limin, SUN Liling, DAI Daoyang, ZHANG Jun & WANG Wenkuiinstitute of physics, Center for Condensed Matter physics, Chinese Academy of Sciences, beijing 100080, china department of materials Science and engineering, yanshan university, qinhuangdao 066004, china institute of physics Center for Condensed Matter Physics Chinese Academy of Sciences Beijing China department of materials Science and engineering Yanshan University Qinhuangdao China

The ZrTiCuNiBe alloy is melt and solidified by Bridgman unidirectional solidification on two gravity field orientations (the gravity field orientation is parallel and opposite to solidification direction). Effects of gravity on morphology and microstructure are investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). When gravity field orientation is parallel to solidificationdirection, less needle-like primary phase is embedded in a matrix eutectic; when gravity field orientation is opposite to solidification direction, a large amount of coarser needle-like primary phases were observed.

关键词： gravity field unidirectional solidification bulk amor- phous alloy.

Large-scale boron nanowire nanojunctions and their highly-oriented arrays

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2004年第5期47卷 621-632页

作者： CAO Limin1,2, ZHANG Ze2 & WANG Wenkui1,2 1. Key Laboratory of Metastable materials Science and Technology, yanshan university, qinhuangdao 066004, china 2. institute of physics, Chinese Academy of Sciences, beijing 100080, china 1. Key Laboratory of Metastable materials Science and Technology Yanshan University 066004 Qinhuangdao China 2. institute of physics Chinese Academy of Sciences 100080 Beijing China

Highly oriented multiple boron nanowire nanojunctions with unilateral feather- like morphology were first successfully prepared using a radio-frequency magnetron sputtering method. The branched boron nano-feathers always nucleate and grow on the same sidewall of the stems, and align in parallel to form multiple T- and/or Y-type nanojunctions. The diameters of the branches and the stems are in the range of 20—40 and 60—80 nm, respectively. The thinner branches and thicker stems of the boron nanowires self-assembled into large-scale, highly ordered arrays on various substrates. During the formation and self-assembly of the arrays, no template or catalyst was needed. We believe that the approach presented here can be used to fabricate heterostructures with bottom-up assembly of a wide variety of one-dimensional nanostructures via the rational design of targets and the proper control of the experimental conditions.

关键词： boron nanowires, nanojunctions, self-assembly, magnetron sputtering.

IN SITU TEM OBSERVATION OF INITIATION AND PROPAGATION OF CRACKS IN NiAlFe INTERMETALLICS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English Letters) 1996年第6期9卷 675-679页

作者： Y.X. Lu C.H. Tao J.W.Zhang M.L.Xue and D.Z. Yang(beijing institute of Aeronautical materials, beijing 100095, china Harbin institute of Technology, Harbin 150001,china yanshan university,qinhuangdao 066004, ) beijing Inst of Aeronautical Materials Beijing China

Formation of the dislocation hoe zone(DFZ),and initiation and propagation of microcracks have been investigated by in situ transmission electron microscope(TEM)tensile test for NiAlFe *** TEM foils are strained,a great number of dislocations are found to emit from a crack tip during microcrack propagation and drive out of the crack tip area,leaving behind a *** maximum normal stress exists in the DFZ, thus nanocracks initiate discontinuously ahead of the crack tip in the highly stressed DFZ. Connection of the main crack and nanocracks results in steady propagation of *** fracture and bluntness of the crack tip indicate that propagation of the crack is a leaping process. The second phase in the NiAlFe alloy obstructs propagation of the crack, which results in deviation of the crack path.

关键词： NiAlFe alloy crack TEM observation

Tensile and compression properties of Zr-based bulk amorphous alloy at different temperatures

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2005年第5期48卷 489-495页

作者： WANG Xu1,3, LOU Decheng1, GAO Zhanjun4, LIU Lei1, LIANG Hongmei1, WANG Qingfeng1, LI Qiang1,3 & MA Mingzhen1,2 1. Key Laboratory of Metastable materials Science & Technology of Hebei, yanshan university, qinhuangdao 066004, china 2. National Key Laboratory for Precision Hot Processing of Metals, Harbin institute of Technology, Harbin 150001, china 3. College of Mechanical engineering, yanshan university, qinhuangdao 066004, china 4. Chinese Academy of engineering, beijing 100038, china 1. Key Laboratory of Metastable materials Science & Technology of Hebei Yanshan University 066004 Qinhuangdao China 2. College of Mechanical engineering Yanshan University 066004 Qinhuangdao China 3. Chinese Academy of engineering 100038 Beijing China 4. National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology 150001 Harbin China

Mechanical properties of the Zr41Ti14Cu12.5Ni10Be22.5 bulk amorphous alloy at different temperatures were investigated. The compression test was carried out on a Gleebe-3200 machine at 345 and 375°C, respectively, in the supercooled liquid region. It is shown that decreasing the compressive rate and increasing temperature have a similar influence trend on the compressive behavior of the bulk amorphous alloy. Room and low temperature tensile strengths were tested on the Instron materials testing system. At low temperature, the tensile strength decreased with decreasing of the testing temperature. Hardness measurement indicated that below the glass transition temperature, the hardness decreased with increasing of the annealing temperature and duration time. It, however, increased when the annealing treatment was performed above the glass transition temperature.

关键词： Zr41Ti14Cu12.5Ni10Be22.5 bulk amorphous alloy, mechanical properties, compressive deformation.

Grain evolution of nano-crystals ZnO under HP and HT

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2006年第3期49卷 281-290页

作者： SHAO Guangjie1, QIN Xiujuan1, LIU Riping1, WANG Wenkui1,2 & YAO Yushu2 1. Key Laboratory of Metastable materials Science and Technology, yanshan university, qinhuangdao 066004, china 2. institute of physics, Chinese Academy of Sciences, beijing 100080, china 1. Key Laboratory of Metastable materials Science and Technology Yanshan University Qinhuangdao 066004 China 2. institute of physics Chinese Academy of Sciences Beijing 100080 China

Grain evolution of nano-crystals ZnO under high temperature and pressure is studied using a cubic high pressure apparatus. The structure, grain sizes and morphology of the samples are characterized by X-ray diffraction and field emission scanning electron microscopy. The results show that the grain sizes of ZnO grow rapidly at temperature 200℃ under pressure. At temperature lower than 300 ℃ (including 300 ℃), the grain sizes of the samples first increase with the pressure increasing from 1 to 3 GPa and later de- crease from 4 to 6 GPa. The activation volume from 1 to 3 GPa and from 4 to 6 GPa is calculated respectively using the phenomenological kinetic grain growth equation at temperature 300 ℃. At temperature higher than 400℃ (including 400 ℃), the grain sizes of the samples increase with the pressure increasing from 1 to 6 GPa. ZnO nano-bulks with good quality can be obtained under the specific conditions.

关键词： nano-crystals ZnO,high temperature and pressure,grain evolution

Compression behavior of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(22.5) bulk metallic glass up to 24 GPa

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2005年第3期48卷 319-324页

作者： LI Gong 1, 2 , ZHAN Zaiji 2 , LIU Jing 3 , YUN Jinku 1 , SUN Liling 2 , LIU Riping 1 , ZHANG Jun 2 & WANG Wenkui 1, 2 1. Key Laboratory of Metastable materials Science and Technology, yanshan university, qinhuangdao 066004, china 2. Center for Condensed Matter physics, institute of physics, Chinese Academy of Sciences, beijing 100080, china 3. BSRF, institute of High Energy physics, Chinese Academy of Sciences, beijing 100039, china 1. Key Laboratory of Metastable materials Science and Technology Yanshan University 066004 Qinhuangdao China 2. Center for Condensed Matter physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 3. BSRF Institute of High Energy Physics Chinese Academy of Sciences 100039 Beijing China

The compression of a Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass (BMG) is investigated at room temperature up to 24 GPa using in-situ high pressure energy dispersive X-ray diffraction with a synchrotron radiation source. The pressure-induced structural relaxation is exhibited. It is found that below about 8 GPa, the existence of excess free volume contributes to the rapid structural relaxation, which gives rise to the rapid volumetric change, and the structural relaxation results in the structural stiffness under higher pressure.

关键词： bulk metallic glass, high pressure, structural relaxation, synchrotron radiation.