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1.
Electron microscopy and x-ray diffraction analysis are used in studying Cu-Fe and Ni-Fe-Al alloys upon their anodic polarization in a cryolite-alumina melt, thus, clarifying the regularities of their dissolution and the formation of oxide coatings. Based on the results obtained, a technique of determining the integral corrosion rate of the alloys is proposed. Original Russian Text ? A.Yu. Filatov, E.V. Antipov, M.I. Borzenko, S.Yu. Vasil’ev, V.M. Denisov, V.V. Ivanov, S.M. Kazakov, Z.V. Kuz’minova, V.K. Laurinavichyute, V.V. Lunin, D.A. Simakov, V.I. Shtanov, 2008, published in Fizikokhimiya Poverkhnosti i Zashchita Materialov, 2008, Vol. 44, No. 6, pp. 664–668.  相似文献   

2.
Both nanobands and macroscopic (up to 3mm-long) filamentous conducting BaV8O21-δ crystals are prepared for the first time by hydrothermal processing of polymerized gels. They show stable electrochemical characteristics acceptable for their usage in newly elaborated secondary cells (batteries). Original Russian Text ? T.L. Kulova, A.M. Skundin, S.B. Balakhonov, D.A. Semenenko, E.A. Pomerantseva, A.G. Veresov, E.A. Goodilin, B.R. Churagulov, Yu.D. Tret’yakov, 2008, published in Zashchita Metallov, 2008, Vol. 44, No. 1, pp. 45–48.  相似文献   

3.
To optimize the structure and properties of alloys, it is necessary to take into account the effect of the self-organization of a dissipative structure with fractal properties at load. This requires the development of self-organizing technologies for material production. Fractal material science takes into account the relation between the parameters of fractal structures and the dissipative properties of alloys. It also takes into account the base properties of highly nonequilibrium systems and the self-organizing process of the fractal structure in bifurcation points. V.S. Ivanova earned her Dr. Tech.Sc. in technical sciences, materials science, at Moscow Power Institute in 1948. She is currently chief expert at A.A. Baikov Institute of Metallurgy. I.J. Bunin earned his Dr. Tech. Sc. in technical science, materials science, at Moscow Engineer-Physical Institute in 1987. He is currently chief research worker at A.A. Baikov Institute of Metallurgy. V.I. Nosenko earned his Dr. Tech. Sc. in technical sciences, mathematical theory of elasticity, at Metallurgical University in 1968. He is currently president of Vita International Corporation. Dr. Nosenko is also a member of TMS.  相似文献   

4.
Die-less drawing, introduced in connection with wire drawing (M. S. J. Hashmi, G. R. Symmons and H. Parvinmehr, J. Mech. Engng Sci.24, 1–4 (1982)) is a process in which reduction in the wire size is achieved by hydrodynamic action. In this system, the conventional die is replaced by a reduction unit of stepped bore geometry. Polymer melts are used as the pressure medium, which, when dragged through the unit by pulling the wire, give rise to drag force and hydrodynamic pressure. The combined effect of these forces cause plastic deformation in the wire. The technique has also been applied to strip drawing (A. H. Memon, G. R. Symmons, M. S. J. Hashmi and R. Crampton, Proc. Inst. Mech. Engng Part E, J. Process Mech. Engng203, 57–65) using polyethylene WVG 23 as the pressure medium. In the present study, polyethyl vinyl acetate has been used as the pressure medium in order to investigate the effect of polymer rheology on the process. Experimental results are presented in this paper, which show that this polymer causes larger reductions in width compared to polyethylene WVG 23. The results also indicate that a reduction in area of the strip in excess of 12% could be achieved in a single pass using this system. These experimental results show a close agreement to theoretical results previously published (A. H. Memon, G. R. Symmons, M. S. J. Hashmi and R. Crampton, J. Inst. Mech. Sci. (in press)).  相似文献   

5.
Calculation of diffuse scattering during h.c.p. to f.c.c. martensitic transition by non-random insertion of deformation faults using a Monte Carlo technique is presented. It is shown that a coherent modulation of wavelength λ = 6d111 can result during such transitions. The intensity and sharpness of the satellite peaks are shown to depend on the volume fraction of the twin-related f.c.c. variants. The predicted satellite peaks are in good agreement with those observed in Co and Co-Ni single crystals undergoing h.c.p. to f.c.c. martensitic transition.  相似文献   

6.
Nanocrystalline materials provide a unique opportunity to investigate deformation mechanisms at an extremely fine microstructural scale. An intriguing question has been whether the deformation mechanisms scale with grain size to the nanocrystalline range or whether there are fundamental changes/transitions. The observations of low-temperature and high-strain-rate superplasticity in nanocrystalline materials with some unique features open up new possibilities for scientific and technological advancements. R.S. Mishra earned his Ph.D. in metallurgy at the University of Sheffield in 1988. He is currently adjunct assistant professor at the University of California at Davis. Dr. Mishra is also a member of TMS. S.X. McFadden earned his B.S. in materials engineering at California Polytechnic State University, San Luis Obispo, in 1996. He is currently a research associate at the University of California at Davis. Mr. McFadden is also a member of TMS. R.Z. Valiev earned his Dr.Sci. in solid-state physics from the Institute for Materials Science, Academy of Sciences of the USSR, Kiev, in 1984. He is currently the scientific director and professor at the Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, Russia. Dr. Valiev is also a member of TMS. A.K. Mukherjee earned his D. Phil. in materials science at Oxford University in 1962. He is currently a professor of materials science at the University of California at Davis. Dr. Mukherjee is also a member of TMS.  相似文献   

7.
In this study, solder-based die-attach processes used to affix GaAs devices to heat-spreading carriers were investigated. The solder microstructures were assessed, focusing on void formation, the response of the solder, the backsurface metallization, and the carrier plating to die attachment and reflow thermal processes. Voided regions were found in all solder joints, with a dramatic sensitivity to temperature cycles. Gold-tin alloy phases were found to dominate the solder microstructure for all of the configurations. The total thermal budget was a critical issue in the formation and transformation of various phases as expected for low-melting-point alloys. The NiV-Au backmetal system was investigated to determine the suitability for die attachment. J.M. Parsey, Jr., earned his Ph.D. in materials science at the Massachusetts Institute of Technology in 1982. He is currently a section manager, advanced materials, at Motorola ESTL. Dr. Parsey is also a member of TMS. S. Valocchi earned her M.S. in mechanical engineering/thermal sciences at Arizona State University in 1989. She is currently a process engineer at Motorola. W. Cronin earned his B.Sc. in electrical engineering at Arizona State University in 1979. He is currently a section manager, metals and thinning, at Motorola. J. Mohr earned his M.S. in materials science at Arizona State University in 1990. He is currently a senior technologist at Motorola. B.L. Scrivner earned his B.S. in business administration at the University of Phoenix in 1994. He is currently a product manager at Motorola. K. Kyler earned his B.S. in chemistry at Brigham Young University in 1987. He is currently a process development engineer at Motorola PCRL.  相似文献   

8.
In this literature review, the present understanding regarding the effects of microstructure, loading conditions, and environments on the fatigue behavior of nickel-based superalloys is reviewed. Authors' Note: Inconel, Incoloy, and Nicalon are registered trademarks. L. Garimella earned his M.S. in materials science and engineering at the University of Tennessee in 1997. He is currently working at an Internet company. Mr. Garimella is a member of TMS. P. K. Liaw earned his Ph.D. in materials science and engineering at Northwestern University in 1980. He is a professor and Ivan Racheff Chair of Excellence in the Department of Materials Science and Engineering at the University of Tennessee. Dr. Liaw is also a member of TMS. D.L. Klarstrom earned his Ph.D. in metallurgical engineering at the University of Wisconsin-Madison. He is currently director of Haynes International. Dr. Klarstrom is also a member of TMS.  相似文献   

9.
目的获得具有高硬度、高韧性的ZrAlN薄膜。方法采用磁控溅射技术在钛合金和单晶Si上沉积不同Al含量的ZrAlN薄膜,对薄膜的微观组织和相结构进行表征,并测试薄膜的硬度(H)、弹性模量(E)和断裂韧性(KIC)。结果当Zr1-xAlxN薄膜x分别为0.05,0.23,0.47,0.63时,对应的硬度依次为24.5,40.1,17.1,19.1 GPa,断裂韧性依次为1.47,3.17,1.13,1.58 MPa·m-0.5。x为0.05和0.23时,Al固溶到ZrN晶粒中,形成NaCl型面心立方(FCC)结构;x为0.47和0.63时,则形成纤锌矿密排六方(HCP)AlN第二相。结论 ZrAlN薄膜的硬度和韧性与相组成密切相关。Al固溶时,ZrAlN的硬度较高,韧性较好;超过固溶极限,形成六方AlN时,ZrAlN硬度较低,韧性较差。相比之下,Zr0.77Al0.23N薄膜同时具备最高的硬度和最高的韧性。  相似文献   

10.
In recent years, it has become apparent that bath smelting may be a suitable technology for treating wastes. Technologies developed by Molten Metal Technology, Ausmelt, Mintek, Techtronics, and the University of Wollongong utilize molten baths of metal and slag to process metal-containing wastes. This paper discusses the similarities and differences between these processes, focusing particularly on the EnvIRONment process. S. Street earned his M.E. in materials engineering at the University of Wollongong in 1994. He is currently a postgraduate student at the University of Wollongong. Mr. Street is also a member of TMS. G. Brooks earned his Ph.D. in extractive metallurgy at the University of Melbourne in 1994. He is currently a senior lecturer in the Department of Materials Engineering at the University of Wollongong. Dr. Brooks is also a member of TMS. L. Reilly earned his assoc. diploma in metallurgy at Wollongong TAFE in 1981. He is currently a technologist at South Coast Equipment Pty. Ltd. H.K. Worner earned his D.Sc. in metallurgy at the University of Melbourne in 1942. He is currently an honorary professor in the Department of Materials Engineering at the University of Wollongong.  相似文献   

11.
A possibility of the cathodic deposition of copper-containing nanopowders from organo-aqueous electrolyte solutions is studied. The dimension of particles is corroborated with a transmission electron microscope. Additions of low-molecular surfactants to aqueous electrolyte solutions lead to a decrease in the limiting cathodic currents thus promoting the formation of finely dispersed powder. Original Russian Text ? S.A. Chulovskaya, A.V. Balmasov, S.A. Lilin, V.I. Parfenyuk, 2006, published in Zashchita Metallov, 2006, Vol. 42, No. 4, pp. 430–433.  相似文献   

12.
The co-reduction of cobalt and molybdate ions with dimethylamine borane in pyrophosphate solutions is shown to produce Co-Mo-B alloy coatings. Molybdate is reduced concurrently with cobalt to metal forming a solid solution in cobalt matrix with a hexagonal lattice. The alloy deposits have a pronounced [001] texture with the easy magnetization direction normal to the coating surface. The composition of alloys is heterogeneous in their thickness. The alloys contain cobalt and molybdenum hydroxide admixtures, as well as intermediate products of molybdenum reduction, in the superficial layers. Original Russian Text ? A.B. Drovosekov, M.V. Ivanov, V.M. Krutskikh, E.N. Lubnin, Yu.M. Polukarov, 2008, published in Zashchita Metallov, 2008, Vol. 44, No. 1, pp. 65–68.  相似文献   

13.
A eutectoid polyhedration of the phase diagram of the Fe-C-Mn system is presented, which shows that the structure of manganese steels can contain eutectoids of two kinds that can be in a state of peritectoid equilibrium with austenite. A conode polyhedration of the diagram is performed as applied to the composition of steel 2G. The structural features ensuring precipitation hardening or composite hardening of steels 20G and 110G13L are considered. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 1, pp. 3–7, January, 2006. The first paper of the series appears in Metalloved. Term. Obrab. Met., No. 2, pp. 11–15 (2005). The second paper appears in Metalloved. Term. Obrab. Met., No. 4, pp. 3–9 (2005). The third paper appears in Metalloved. Term. Obrab. Met., No. 9(603), pp. 3–7 (2005).  相似文献   

14.
Recent progress in variational methods helps to provide general principles for microstructural evolution. Especially when several processes are interacting, such general principles are useful to formulate dynamical equations and to specify rules for evolution processes. Variational methods provide new insight and apply even under conditions of nonlinearity, nondifferentiability, and extreme anisotropy. Central to them is the concept of gradient flow with respect to an inner product. This article shows, through examples, that both well-known kinetic equations and new triple junctions motions fit in this context. W. Craig Carter earned his Ph.D. in materials science at the University of California at Berkeley in 1989. He is currently a research scientist at the National Institute of Standards and Technology. J.E. Taylor earned her Ph.D. in mathematics at Princeton University in 1973. She is currently a professor at Rutgers University. J.W. Cahn earned his Ph.D. in chemistry at the University of California at Berkeley in 1952. He is currently a metallurgist at the National Institute of Standards and Technology. Dr. Cahn is also a fellow of TMS.  相似文献   

15.
王绪仁  卫文启 《硬质合金》1996,13(4):247-249
采用发射光谱载体分馏法测定WO3中Zn、Zr、Sr、Ba、Ag的含量.试验中,选择了含3.5%氟化锂、4.0%碳酸锂的石墨粉作缓冲剂,选择了适宜的分析线和光谱测定条件.测定下限分别为:Zn、Zr0.001%,Ba0.0007%,Sr0.0005%,Ag0.0002%.  相似文献   

16.
Suppressing both the vital activity of sulfate-reducing bacteria and hydrogen diffusion through a steel membrane by AMDOR IC inhibitors is studied at a free-corrosion potential, as well as cathodic and anodic polarization, of the membrane working surface. Original Russian Text ? V.I. Vigdorovich, M.V. Vigdorovich, A.V. Ryazanov, A.N. Zavershinskii, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 1, pp. 103–107.  相似文献   

17.
By a FTIR-spectroscopy, an interaction of hydrogen with carbon monoxide adsorbed at an iridium-rhodium bimetallic nanosystem was revealed. This interaction weakens the carbon-oxygen bond, resulting in partial removal of CO from the adsorbent; the process depends on the composition of the nanoparticle surface and the reaction temperature. Original Russian Text ? N.P. Sokolova, R.A. Bulgakova, I.A. Gagina, A.M. Gorbunov, 2008, published in Zashchita Metallov, 2008, Vol. 44, No. 3, pp. 252–254.  相似文献   

18.
The adsorption mechanism of corrosion inhibitors prepared from the modified vegetable oil (MG-ChDTU and MGS) and the water-soluble fraction of vegetable product wastes (FES) was studied. It was found that the inhibitors both chemisorb and physically adsorb at steel to form polymolecular protective layers. Original Russian Text ? O.I. Sizaya, O.N. Savchenko, A.A. Korolev, V.G. Ushakov, 2008, published in Zashchita Metallov, 2008, Vol. 44, No. 3, pp. 267–271.  相似文献   

19.
钛的α相选区电子衍射花样(SADP)标定的实践表明,现有的方法,包括标准图表和计算机程序在标定时只能对h.c.p.结构晶体部分的SADP实现正确的标定。运用纯hkl法和根据h.c.p.结构衍射条件及二次衍射规律编制的分析用计算机程序,可实现h.c.p.结构晶体全部SADP的正确标定  相似文献   

20.
李超  卢娜  李东亮  张剑凯 《金属学报》2004,9(9):1045-1049
目的: 探讨黄体酮(progesterone, PROG) 对脑缺血再灌注损伤的保护机制。方法: 采用SD 大鼠局灶性脑缺血再灌注模型(transient middle cerebral artery occlusion,MCAO) 。将大鼠随机分为6 组:假手术组、ischmia/reperfusion (I/R) 组、溶剂(二甲基亚砜dimethyl sulfoxide, DMSO) 对照组、PROG 预防组、PROG 治疗组、PROG 预防并治疗组, 对各组动物脑缺血/再灌注后神经功能缺陷进行计分, 并应用细胞死亡原位末端标记(insitu end labeling, ISEL) 法研究脑组织细胞凋亡情况。结果: (1) 缺血2 h 再灌注24 h 后神经功能缺陷计分:假手术组为0 分, I R 组为1. 38±0. 92, DMSO 组为1. 0±0. 53, 预防组为0. 35±0. 51, 治疗组为0. 62±0. 52, 防治组为0. 25±0. 46 。(2) 高倍视野下凋亡细胞数:假手术组为1. 88±0. 25, I R 组为41. 38±3. 85, DMSO 组为38. 13±5. 69, 预防组为22. 88±2. 70, 治疗组为25. 63±2. 93, 防治组为20. 88±2. 30 。以上指标各药物处理组(预防组、治疗组及防治组) 与I R 组、DMSO 对照组之间差异具有统计学意义(P<0. 05) 。结论: PROG 可减少局灶性缺血再灌注脑损伤动物模型神经功能缺失的发生, 减轻局灶性缺血再灌流脑损伤, 减少大鼠缺血再灌注后脑细胞凋亡。  相似文献   

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