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Effect of Multiple Martensitic Transformations on Structure of Fe-Ni Alloys

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Journal of Materials Science & Technology 2013年第3期29卷 279-282页

作者： V.Danilchenko Ie.Dzevin V.Sagaradze G.V.Kurdyumov Institute of Metal Physics NAS of UkraineKievUkraine Institute of Metal Physics Ural Division of RASEkaterinburgRussia

Effect of multiple direct and reverse martensitic transformations on fragmentation of austenitic grains in Fe-Ni alloys have been studied by X-ray diffraction and scanning electron microscopy. An ultra-fine structure was formed by fragmentation inside austenitic grains due to progressing misorientation of austenitic sub-grains during multiple γ-α-γ-martensitic phase transitions. An increase in the number of γ-α-γ-transformations increases misorientation angle between austenitic sub-grains and leads to transformation of an austenitic single crystal into a textured polycrystal. It has been shown that multiple γ-α-γ-martensitic phase transitions change the mechanism of internal stress relaxation from dislocation-based to deformation twinning.

关键词： Austenite crystal lattice Ultra-fine structure Martensitic transformation

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NANO-MOIRE METHOD

Acta Mechanica Sinica 1999年第3期15卷 283-288页

作者：戴福隆邢永明 Department of Engineering Mechanics Tsinghua UniversityBeijing 100084China

Nano-moiré method presented in this paper is an experimental technique which allows direct measurement of nanoscopic mechanical parameters, such as displacement, strain and dislocation distribution. The basic idea is the formation of moiré fringes when a HREM (high resolution electron microscopy) image of crystal material is superimposed with a unidirectional grating. Fourier filtering technique is used to increase the contrast of fringes and to multiple the fringes. This method has atom-size sensitivity and spatial resolution, and relatively large range. It provides a new experimental technique with very high sensitivity and spatial resolution for nanomechanics.

关键词： Nano-moiré crystal lattice nano-deformation experimental moiré

Nanocrystal Model for Liquid Metals and Amorphous Metals

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Journal of Materials Science & Technology 2010年第1期26卷 69-74页

作者： X.L. Tian, C.W. Zhan, J.X. Hou, X.C. Chen and J.J. Sun Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061, China Key Laboratory of Liquid Structure and Heredity of Materials Ministry of Education Shandong University Jinan 250061 China

A nanocrystal model for liquid metals and amorphous metals has been developed. With the nanocrystal model, the broadening peak profiles （BPPs） of Cu, Al, Al65Cu20Fe15 alloy, Cu7oNi30 alloy and Fe50Si50 alloy were gained by broadening the X-ray diffraction （XRD） peaks of a crystal lattice. By comparing the BPPs with the XRD intensity curves measured on the liquid metals, it is found that the BPPs are closely in agreement with the XRD intensity curves, respectively, except the FesoSiso alloy. Therefore, the nanocrystal model can be used to determine if the atomic cluster structure of the liquid metal is similar to the structure of its crystal lattice.

关键词： Liquid metal Atomic cluster Structure crystal lattice

Improving rate performances of Li-rich layered oxide by the co-doping of Sn and K ions

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Journal of Materiomics 2019年第2期5卷 149-155页

作者： Bao Li Xinbo Wang Yibo Gao Bao Wang Jinxu Qiu Xu Cheng Dongmei Dai School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiangHenan453007China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing100190China

The specific capacities and power performances of conventional cathode materials are still needed to improve in order to meet the demand for electrical ***-rich layered oxide delivers a high specific capacity,but poor rate *** doping is an effective way to address this challenge due to the expanded crystal *** a single ion substitution in the literature,here Li-rich layered oxides were doped by Sn and K to achieve the favorite rate performance,where Sn and K were assumed to replace transition metal ion and Li ion,*** indicate the co-doped samples result in an increasing capacity retention by more than 40%from 107.9(contrast sample)to 151.5 mAh g^(-1)(co-doped sample)at 10 *** impedance spectroscopy(EIS)and calculated diffusion coefficient of Li^(+) also confirmed the favorite rate performances for co-doped *** results of Rietveld structure refinement,we proposed that the reason for rate performances comes from the enlarged crystal lattices,which provides a smooth diffusion tunnel for Lithium ions during the charge/discharge *** as-adopted method provides a possibility to achieve the improved rate performances by co-doping big-size ions at the different crystal sites.

关键词： Li-rich layered oxide Rate performance Sn-doping K-doping crystal lattice Solid state reaction

Effect of Roasting Conditions of Rich Cerium Rare Earth Carbonate on crystallite Morphology and Polishing Ability of Ceria-Based Rare Earth Oxide

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Journal of Rare Earths 2007年第S1期25卷 125-128页

作者：吴文远李学舜陈杰杨国胜涂赣峰 School of Materials and Metallurgy Northeastern University Baotou Tianjiao Seimi Rare-Earth Polishing Powder Co. Ltd.

The granule shape and crystal structure of the the ceria-based rare earth oxide which were roasted at 600～1050 ℃ for 2～6 h and then cooled in furnace, cooled out of furnace or cooled in water were studied by means of XRD and SEM. The results revealed that the rich cerium rare earth carbonate could be changed into the rare earth oxide which was a kind of sandwich made of globose granule whose diameter was between 0.5～3.0 μm after being roasted in 900 ℃ for 2 h. This kind of crystal lattice in rare earth oxide belonged to face-centered cubic lattice and its space between crystal surface {111} and {200} (viz. L111 and L200) would enlarge as the roasting temperature increasing. With increasing roasting temperature, L111 would rise straightly upward, and L200 would rise straightly upward when roasting time was 2～4 h but changed little when roasting time was 4～6 h. The glass-polishing experiments found that the polishing ability of the ceria-based rare earth oxide was the best as L111 was 43～53 nm and the L200 was 43～56 nm.

关键词： polishing powder ceria-based rare earth oxide crystal lattice polishing ability rare earths

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环境友好的熏蒸剂发生与残渣再资源化研究

环境友好的熏蒸剂发生与残渣再资源化研究

作者：翟燕萍天津大学

学位级别：硕士

熏蒸法是防治储粮害虫最为有效的手段,磷化氢是目前对人类而言最为安全的熏蒸剂,也是绝大多数国家唯一允许使用的熏蒸剂。但目前,绝大多数熏蒸方法都存在磷化氢发生工艺不完善,熏蒸有毒残渣难以处理等棘手的问题。本论文根据磷化氢水解... 详细信息

熏蒸法是防治储粮害虫最为有效的手段,磷化氢是目前对人类而言最为安全的熏蒸剂,也是绝大多数国家唯一允许使用的熏蒸剂。但目前,绝大多数熏蒸方法都存在磷化氢发生工艺不完善,熏蒸有毒残渣难以处理等棘手的问题。本论文根据磷化氢水解反应和粮食储备库环流熏蒸的特点,在已有磷化氢高效发生技术的基础之上,系统研究了磷化氢发生反应的最佳工艺条件。研究表明:CO2气体搅拌完全可以代替传统的机械搅拌,CO2除对反应溶液起到搅拌和阻燃保护作用以外,还能打破反应溶液的酸碱和反应平衡状态,促使磷化铝水解反应进行得更快、更彻底;将反应温度保持在 40℃～55℃,不仅可以防止磷化铝低温时的团聚,保证反应的彻底进行,还可减轻熏蒸气进入粮仓前除水分工艺的负荷,避免水蒸气随熏蒸气体进入粮仓。改进后的磷化氢发生工艺,在粮库现场应用试验效果良好,整个磷化氢发生及输配过程快速、稳定、安全、彻底,能源消耗低,熏蒸杀虫效果好。添加了特定添加剂的熏蒸残渣,可以被有效处理至无害化,且不再产生“三废”污染;采用普通干燥法,可使操作更安全、经济,并且不影响氧化铝样品的品质。采用 XRD、TEM、BET、EPMA、XPS 和 TPD 等手段对样品进行的表征研究显示:残渣再资源化得到的纳米 Al2O3样品,经 500℃煅烧 3h 后,形成比表面积为 267.66m2.g-1,孔容为 0.61cm3.g-1的γ-Al2O3;经 1000℃煅烧,γ-Al2O3晶型完整,并且仍保持 161.87m2.g-1的高比表面积以及 0.58cm3.g-1的孔容。可见残渣再资源化得到了高热稳定性的活性氧化铝。残留在 Al2O3样品中的磷元素进入 Al2O3的体相晶格,占据γ-Al2O3的四面体配位空穴;经高温煅烧后,磷要向氧化铝表面迁移、富集,因此大大延迟了γ-Al2O3向α-Al2O3的转变,提高了样品的热稳定性。

关键词： phosphine Churned up by CO2 poisonous fumigating residue γ-Al2O3 crystal lattice thermal stability