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稀有金属材料与工程 2011年第S3期40卷 346-349页

作者： Yan Wuwei1, Zhang Chengxiao1, Zhang Guofang1, Jin Lihua2. Li Chengshan2. Yan Guo2. Lu Yafeng2.1 Shaanxi Normal University,{2.’an 710062. China 2.northwest institute for nonferrous metal research,{2.’an 710016, China Shaanxi Normal Univ Xian 710062 Peoples R China NW Inst nonferrous Met Res Xian 710016 Peoples R China

Preparation and characterization of the YBCO superconducting films by chemical solution route with polyethylene glycol (PEG2.0) and Cu(NO3)2.as precursors are presented. It was found that PEG2.0 and sucrose were novel chelates and Cu (NO3)2.was an alternative precursor for the preparation of YBCO superconducting film by chemical solution route. The precursor solution was prepared by mixing yttrium trifluoroacetate, barium trifluoroacetate, and copper nitrate in solvent of methanol with chelates including PEG2.0 and sucrose. YBCO films were prepared by coating the precursor solution on LaAlO3 single crystal substrate, following vacuum drying, rapid calcining, firing and oxygen annealing. The prepared films were characterized by optical microscope (OM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that films were crack-free and homogeneous, stronger tendency of (00l) texture, uniform with less pore, pure c-axis orientation. The films showed good superconducting properties, with Tc of 90 K and critical current density (Jc) of 1 MA/cm2.(77 K, 0 T). This work demonstrates that the developed method is a promising method for preparation of YBCO superconducting film which has a fine superconducting characterization with advantages of simple and rapid.

关键词： coated conductor YBCO chemical solution deposition PEG2.0 copper nitrate sucrose

Processing research on Shaping Porous 316L Stainless Steel via SLS

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稀有金属材料与工程 2011年第S3期40卷 206-210页

作者： Yang Lijun 1, Dang xinan1, Zhou Lian 1,2. Chen Qiaofu 1, Wang Lili 1 1Shaanxi University of Science & Technology, xi’an 71002., China 2.3} institute for {2. metal research, xi’an 710016, China Shaanxi Univ Sci & Technol Dept Mechanoelect Engn Xian 710021 Peoples R China NW Inst nonferrous Met Res Xian 710016 Peoples R China

The principles of selective laser sintering (SLS) were applied in this experiment .The influence of laser power, scan distance, scan speed and other processing parameters of fiber laser on the pore properties, elastic modulus, and micro morphology, etc were investigated in this paper. Tests were conducted on 316L stainless steel powder. The results showed that porous metal material that meets the requirements of porous bionic human bone material (porosity of 33.4%-37.8%, average pore radius of 94.2.178 μm, elastic modulus of 7.43-12.76 GPa, nearly spherical regular pore) can be produced when sintered at 90-100 W laser power, with a scan speed of 2.-2. mm/s and scan distance of 0.165 mm.

关键词： selective laser sintering material power processing parameters porosity

Effect of excess Y_2._3 addition on the physical properties of melt processed YBCO bulks

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Science China(Physics,Mechanics & Astronomy) 2004年第1期47卷 17-23页

作者： YANG Wanmin1,2.3, ZHOU Lian2. FENG Yong2. ZHANG Pingxiang2. WU Minzhi3 & W. GAWALEK3 1. Department of Physics, Shaanxi Normal University,{2.抋n 710062. China 2. northwest institute for {2. metal research.{2.抋n 710016, China 3. institute fur Physikalische Hochtechnologie e.V(IPHT), Jena, Germany Correspondence should be addressed to Yang Wanmin (email: wm-yang@***) Received June 2., 2.03 1. Department of Physics Shaanxi Normal University 710062 Xi’an China 2. northwest institute for{2. metal research 710016 Xi’an China 3. institute fur Physikalische Hochtechnologie e.V (IPHT) Jena Germany

The YBCO superconductors with Y2.3 addition were prepared by a modified melt textured process and the effects of excess Y2.3 addition on the physical properties of melt textured YBCO have been investigated. It is found that the melt temperature of YBCO samples decreases drastically with the increasing Y2.3, and the maximum levitation forces are drastically different for samples with different Y2.3 addition. It is also found that the optimal Y2.3 addition to YBCO is about 10wt%. Considering the microstructure and the starting composition, the results are well discussed and interpreted.

关键词： YBCO superconductor, melt growth, Y2.3 addition, levitation force.

Effect of HT on the Interface Diffusion and Microstructure of Cu-Nb Micro-composites

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稀有金属材料与工程 2011年第S3期40卷 376-379页

作者： Liang Ming, Lu Yafeng, Sun Lufei, Li Chengshan, Yan Guo northwest institute for{2. metal research, xi’an 710016, China NW Inst nonferrous Met Res Superconducting Mat Res Ctr Xian 710016 Peoples R China

We have fabricated high strength and conductivity Cu-Nb micro-composites by bundling and drawing process. The interface diffusion and microstructure of Cu-17vol% Nb composites experienced severe plastic deformation at different heat treatment conditions are investigated. Diffusion at Cu/Nb interface of Nb filaments is observed by scanning electron microscopy and energy dispersive X-ray spectroscopy. The interface characteristic and edge spheroidization of Nb filaments are discussed.

关键词： Cu-Nb heat treatment microstructure diffusion

Transition Temperature of Bi_2.r_2.aCu_2._(8+x) Superconducting Films Prepared from Commercial Precursors

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稀有金属材料与工程 2011年第S3期40卷 368-371页

作者： Bi Yue1, Wang Sansheng1, Hao Qingbin2.1 Inertial technology Key Laboratory of Fundamental Science for National Defense, Beihang University, Beijing 100191, China 2.northwest institute for nonferrous metal research, xi,{2., China Beihang Univ Sch Instrument Sci & Optoelect Engn Inertial Technol Key Lab Fundamental Sci Natl Def Beijing 100191 Peoples R China NW Inst nonferrous Met Res Xian 710016 Peoples R China

This paper have made a systematic study of the superconducting Bi-2.12.phase transition temperature, which has a transition temperature (Tc) around 80-93 K, and depends on precise control of synthesis conditions, mainly including heat treatment parameters, oxygen partial pressure, and annealing temperature. Partial melting of the sample during preparation helps to raise its Tc. To elucidate the origin of this strong effect, the samples were heated with different melting process. The rapid changes in Tc value are associated with small changes in oxygen content, which depends on the annealing temperature and the oxygen partial pressure. We have optimized the above mentioned parameters for Bi-2.12.film, and Tconset was improved to 93 K.

关键词： Bi-2.12 phase partial melt process transition temperature

Large Ti_3SiC_2.Bulks Fabricated by Infiltration Method

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稀有金属材料与工程 2011年第S3期40卷 372-375页

作者： Shan Di, Yan Guo, Zhou Lian, Li Chengshan, Wang Qingyang, xiong xiaomei {2. institute for {2. metal research, xi’an 710016, China NW Inst nonferrous Met Res Superconducting Mat Ctr Xian 710016 Peoples R China

T3SiC2.bulks have been synthesized by infiltrating Si liquid into porous precursor pellets composed of solid Ti and C powders. Silicon pellets were placed at the bottom of the precursor pellets as the liquid source. The starting compositions can be represented by the formula 3Ti + 2. + xSi, where x = 1.0, 1.2. 1.4 and 1.6, respectively. The phase formation and microstructure of the bulks were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results demonstrated that the Ti/C precursor pellet could only react with Si completely when the x value is 1.6. Large, a purity of above 95wt% Ti3SiC2.bulk of up to 50 mm in diameter was obtained by this method.

关键词： infiltration method Ti3SiC2 bulks Si content 50 mm in diameter

Impact factors of fractal analysis of porous structure

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Science China(Technological Sciences) 2010年第2期53卷 348-351页

作者： TANG HuiPing, ZHU JiLei, xi ZhengPing, DI xiaoBo, WANG JianYong & AO QingBo State Key Laboratory of Porous {2. Materials, northwest {2. for nonferrous {2. research, xi’an 710016, China 1. State Key Laboratory of Porous metal Materials Northwest Institute for Nonferrous Metal Research Xi’an 710016 China

Characterization of pore structure is one of the key problems for fabrication and application research on porous materials. But, complexity of pore structure makes it difficult to characterize pore structure by Euclidean geometry and traditional experimental methods. Fractal theory has been proved effective to characterize the complex pore structure. The box dimension method based on fractal theory was applied to characterizing the pore structure of fiber porous materials by analyzing the electronic scanning microscope (SEM) images of the porous materials in this paper. The influences of image resolution, threshold value, and image magnification on fractal analysis were investigated. The results indicate that such factors greatly affect fractal analysis process and results. The appropriate magnification threshold and fractal analysis are necessary for fractal analysis.

关键词： porous materials fractal dimension porous structure

Mechanism of Burn Resistance of Alloy Ti40

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Journal of Materials Science & Technology 2001年第6期17卷 677-678页

作者： Yongqing ZHAO, Lian ZHOU,Kanging ZHU,Henglei QU and Huan WU northwest institute for{2. metal research, xi’an 710016, China [Manuscript received June 5, 2.00] NW Inst nonferrous Met Res Xian 710016 Peoples R China

The Ti fire found in high performance engines promotes the development of burn resistant Ti alloys. The burn resistant mechanism of Ti40 alloy is investigated. Ti40 alloy reveals good burn resistance. Its interfacial products between burning products and the matrix are tenacious, which retard the diffusion of oxygen into the matrix. Two burn resistant mechanisms, that is, fast scatter dispersion of heat and suppression of oxygen diffusion, are proposed.

关键词： Ti Mechanism of Burn Resistance of Alloy Ti40

Effect of Annealing Ways on the Formation of Cube Texture in Ni-5at% W Substrates for YBCO Coated Conductors

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稀有金属材料与工程 2011年第S3期40卷 322-324页

作者： Chen xingpin1, Shang Du1, Chen Xue1, Ji Yongbin2. Ji Ping2. Li Chengshan2. Liu Qing1 1 Chongqing University, Chongqing 400030, China 2.northwest institute for nonferrous metal research, xi’an 710016, China Chongqing Univ Coll Mat Sci & Engn Chongqing 400030 Peoples R China NW Inst nonferrous Met Res Xian 710016 Peoples R China

Two annealing ways, single-step annealing (SSA) and two-step annealing (TSA), were carried out to investigate the formation of the cube texture during recrystallization in the highly rolled Ni-5at%W alloy by means of EBSD and XRD techniques. It was found that both the microstructure and cube texture of the highly rolled substrates depended strongly on the annealing ways. The TSA method yields sharper cube texture and higher proportion of low-angle grain boundaries compared with SSA method. In addition, the TSA method suppresses the formation of annealing twins during recrystallization and improves the degree of the in-plane alignment of the cube grains in the alloy slightly.

关键词： cube texture nickel alloys recrystallization grain boundaries

Surface Modification of NiW Alloy Substrates

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稀有金属材料与工程 2011年第S3期40卷 380-382页

作者： Wang Xue1, 2. Li Chengshan2. Yu Zeming2. Zheng Huiling2. Ji Yongbin2. Chen Zewen 1, 2. Fan Zhanguo 1 1Northeastern University, Shenyang 110004, China 2.0} institute for Non-ferrous{2. research, xi’an 710016, China NW Inst nonferrous Met Res Superconducting Mat Res Ctr Xian 710016 Peoples R China Northeastern Univ Shenyang 110004 Peoples R China

We have studied the adsorption of elemental S on the surfaces of NiW alloy substrates where elementary sulfur was used as sulfur source. Compared with those previous investigations which used H2. as the sulfur source and operated in an ultra-high vacuum chamber, we used elemental sulfur as the sulfur source which does not need an ultra-high vacuum chamber but Ar-H protection atmosphere in the process of sulfuration. After sulfuration, epitaxial LZO buffer layers were deposited on these substrates directly. The samples were investigated by means of AFM, XPS, SEM and XRD in this study. The results show that after sulfuration, S forms a c (2.2. structure at a coverage of 0.5 ML, in agreement with previous results, representing the effectiveness of elemental sulfur during the sulfuration process. The c (2.2.-S superstructure on the surface of the NiW substrates has optimized the La2.r2.7(LZO) buffer layer texture.

关键词： NiW substrates sulfuration c (2.2. structure buffer layer