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Dynamic Mechanical Behavior and Adiabatic Shear Bands of Ultrafine Grained Pure zirconium

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Journal of Wuhan University of Technology(Materials Science) 2020年第1期35卷 200-207页

作者：刘晓燕 YANG Cheng YANG Xirong LUO Lei HE Xiaomei KANG Shumei School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051China

Dynamic compression tests were carried out to investigate dynamic mechanical behavior and adiabatic shear bands in ultrafine grained(UFG)pure zirconium prepared by equal channel angular pressing(ECAP)and rotary *** cylindrical specimens were deformed dynamically on the split Hopkinson pressure bar(SHPB)at different strain rates of 800 to 4000s^-1 at room *** temperature distribution of the shear bands was estimated on the basis of temperature rise of uniform plastic deformation stage and thermal diffusion *** results show that the true stress-true strain curves of UFG pure zirconium are concave upward trend of strain in range of 0.02-0.16 due to the effects of strain hardening,strain rate hardening and thermal *** formation of the adiabatic shear bands is the main reason of UFG pure zirconium failure.A large number of micro-voids are observed in the adiabatic shear bands,and the macroscopic cracks develop from the micro-voids *** fracture surface of UFG pure zirconium exhibits quasi cleavage fracture with the characteristic features of shear dimples and river *** highest temperature within the shear bands of UFG pure zirconium is about 592 K.

关键词： ultrafine grained pure zirconium dynamic compression adiabatic shear bands thermal diffusion

EFFECTS OF zirconium ON MICROSTRUCTURES AND MECHANICAL PROPERTIES OF MICROALLOYED STEELS

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Acta Metallurgica Sinica(English Letters) 2006年第5期19卷 319-327页

作者： T．H．Xi X. Chen P.H. Li Z.X. Yuan Technology Center of Wuhan Iron ＆ Steel （Group） Corp. Wuhan 430080 China School of Materials and Metallurgy Wuhan University of Science and TechnologyWuhan 430081 China

The effects of Zr on the microstructures and mechanical properties of microalloyed steels have been investigated by mechanical tests and microstructural observations. The microstructures in the Zr-doped steels are ferrite plus pearlite, which is similar to those in the Zr-free steel. With the increase in the Zr content, the lamellar structure reduces and even disappears. Sulfides and silicates that exist in the Zr-free steel are modified into fine oxides in the Zr-bearing steel. When the Zr contents range from 0.01wt% to 0.03wt%, the low temperature toughness of the steel can be substantially improved while its room-temperature strength and ductility have no apparent change. The refinement of ferrite grain size by the addition of zirconium is one of the main reasons for this toughness improvement.

关键词： zirconium microalloyed steel microstructure mechanical property

Effect of the pore size of Co/SBA-15 isomorphically substituted with zirconium on its catalytic performance in Fischer-Tropsch synthesis

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Science China Chemistry 2010年第12期53卷 2551-2559页

作者： TAO CongLiang 1,LI JinLin 1 & LIEW Kong Yong 1,2 1 Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education South-central University for Nationalities,Wuhan 430074,China 2 Faculty of Industrial Science and Technology,University Malaysia Pahang,Gambang 26300,Kuantan,Pahang,Malaysia Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education South-central University for Nationalities Wuhan China Faculty of Industrial Science and Technology University Malaysia Pahang Gambang Malaysia

Cobalt catalysts supported on a series of mesoporous SBA-15 materials isomorphically substituted with zirconium (Zr/Si atomic ratio=1/20) with different pore sizes (5.7 nm,7.8 nm,11.6 nm,17.6 nm) have been *** catalysts were characterized by transmission electron microscopy,29 Si solid state magic angle spinning (MAS)NMR,N2 adsorption-desorption measurements,X-ray powder diffraction,X-ray photoelectron spectroscopy,H2-temperature programmed reduction,H2-temperature programmed desorption and O2 *** results indicated that larger pore size led to weaker interactions between cobalt and the supports which lowered the temperature of both reduction steps (Co3O4 → CoO and CoO→ Co0).The catalytic performances of the catalysts in Fischer-Tropsch synthesis (FTS) were tested in a fixed bed *** was found that the FTS catalytic activity and product selectivity depended strongly on the pore size of the *** catalyst with a pore size of 7.8 nm showed the best FTS activity,and the catalyst with a pore size of 17.6 nm showed the highest selectivity to C12-C20 and C20+ hydrocarbons.

关键词： Fischer-Tropsch synthesis cobalt catalyst SBA-15 pore size zirconium isomorphic substitution

Developing an interatomic potential for martensitic phase transformations in zirconium by machine learning

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npj Computational Materials 2018年第1期4卷 254-261页

作者： Hongxiang Zong Ghanshyam Pilania Xiangdong Ding Graeme J.Ackland Turab Lookman State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China Theoretical Division&Materials Science and Technology Division Los Alamos National LaboratoryLos AlamosNM 87545USA Centre for Science at Extreme Conditions(CSEC) School of Physics and AstronomyUniversity of EdinburghEdinburgh EH93FDUK

Atomic simulations provide an effective means to understand the underlying physics of structural phase ***,this remains a challenge for certain allotropic metals due to the failure of classical interatomic potentials to represent the multitude of *** on machine-learning(ML)techniques,we develop a hybrid method in which interatomic potentials describing martensitic transformations can be learned with a high degree of fidelity from ab initio molecular dynamics simulations(AIMD).Using zirconium as a model system,for which an adequate semiempirical potential describing the phase transformation process is lacking,we demonstrate the feasibility and effectiveness of our ***,the ML-AIMD interatomic potential correctly captures the energetics and structural transformation properties of zirconium as compared to experimental and density-functional data for phonons,elastic constants,as well as stacking fault *** dynamics simulations successfully reproduce the transformation mechanisms and reasonably map out the pressure–temperature phase diagram of zirconium.

关键词： martensitic transformation zirconium

Methyl and methane elimination in the gas phase reaction of zirconium atom with 2-butyne:A DFT study

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Chinese Chemical Letters 2010年第12期21卷 1501-1504页

作者： Tao Hong Li Chuan Ming Wang Xiao Guang Xie Department of Chemistry Southwest Forestry University Kunming 650224 China Department of Biology Honghe University Menzi 661100 China Department of Chemistry Yunnan University Kunming 650091 China

The mechanisms for CH3- and CH_4-elimination in the gas phase reaction of ground-state Zr with 2-butyne has been investigated in detail using B3LYP *** the elimination of CH3,two mechanisms which are similar to those previously found for the reactions of Y and Zr with propyne are *** mechanism for the elimination of CH_4 was revealed as：Zr ＋ CH3C≡CCH_3→π-complex→TS（H-migration）→HZr-（H2CCC）-CH3→TS（C-C insertion）→（H2CCC）-HZr-CH3→TS（H-migration）→CH4＋ ZrC3H2.

关键词： Mechanism zirconium 2-Butyne B3LYP

A Novel zirconium-Based Perovskite-Type Membrane Material for Oxygen Permeation

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Chinese Chemical Letters 2001年第9期12卷 835-838页

作者： Jian Hua TONG Wei Shen YANG Rui CAI Bai Chun ZHU State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of SciencesP.O.Box 110Dalian 116023

A novel zirconium-based membrane material of BaCo0.4Fe0.4Zr0.2O3-6 with cubic perovskite structure was synthesized for the first time through a method of citric and EDTA acid combined complexes. The structural stability was characterized by XRD, O-2-TPD and H-2-TPR techniques respectively. The high oxygen permeation flux of 0.873 mL/cm(2) min at 950 degreesC was obtained under He/Air gradient. Meanwhile, the single activation energy for oxygen permeation and the long-term steady operation of 200 h at 800 degreesC were achieved.

关键词： Perovskite mixed-conducting oxygen separation zirconium

Trace Determination of zirconium(Ⅳ) by Anodic Adsorptive Voltammetry at a Carbon Paste Electrode

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Chinese Chemical Letters 2004年第11期15卷 1315-1318页

作者： XunMAO HuanXinLAI JuNanLI PengGAO ZhiHongYAN CollegeofChemistryXiangtanUniversity Xiangtan411105

A new sensitive adsorptive voltammetric method was described for the determination of zirconium at a carbon paste electrode (CPE) in the presence of alizarin complexone (ALC). Optimal analytical conditions are: 1.0?0-6 or 5.0?0-7 mol/L ALC, 0. 20 mol/L HAC-NaAc (pH 4.3), accumulation for 60 s at 0 V (vs. SCE), and linear scanning from 0 V to 1.0 V at 250 mV/s. The peak potential of the complex is at 0.81 V. By using a model JP-303 polarographic analyzer, 2.0?0-10 mol/L (S/N=3) zirconium can be detected with a 90 s accumulation, when the 2nd-order derivative linear sweep technique is used, and the linear range is 6.0?0-10-2.0?0-8 mol/L (5.0?0-7 mol/L ALC) and 2.0?0-8-2.0?0-7 mol/L (1.0?0-6 mol/L ALC), respectively. The developed method was applied to the determination of trace zirconium in the ore samples with satisfactory results.

关键词： zirconium alizarin complexone carbon paste electrode anodic adsorptive voltamme- try.

Synthesis and Characterization of Bis（guanidinate） zirconium Complexes

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Chinese Journal of Chemistry 2005年第9期23卷 1193-1197页

作者：庞兴安姚英明王俊峰盛鸿婷张勇沈琪 Department of Chemistry and Chemical Engineering Suzhou University Suzhou Jiangsu 215006 China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China

Addition of one equivalent of LiN（i-Pr）2 or LiN（CH2）5 to carbodiimides, RN=C=NR [R=cyclohexyl （Cy）, isopropyl （i-Pr）], generated the corresponding lithium of tetrasubstituted guanidinates {Li[RNC（N R^′2）NR]（THF）}2 [R=i-Pr, N R^′2=N（i-Pr）2 （1）, N（CH2）5 （2）; R=Cy, N R^′2=N（i-Pr）2 （3）, N（CH2）5 （4）]. Treatment of ZrCl4 with freshly prepared solutions of their lithium guanidinates provided a series of bis（guanidinate） complexes of Zr with the general formula Zr[RNC（N R^′2）NR]2Cl2 [R=i-Pr, N R^′2=N（i-Pr）2 （5）, N（CH2）5 （6）; R=Cy, N R^′2=N（i-Pr）2 （7）, N（CH2）5 （8）]. Complexes 1, 2, 5-8 were characterized by elemental analysis, IR and ^1H NMR spectra. The molecular structures of complexes 1, 7 and 8 were further determined by X-ray diffraction studies.

关键词： guanidinate zirconium crystal structure

Copolymerization of Ethylene/1-hexene and Polymerization of Propylene with Cp-indenyl zirconium Complexes

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Chinese Journal of Chemistry 2005年第8期23卷 1081-1084页

作者：张勇杨晓霞余亦华钱延龙黄吉玲 The Laboratory of Organometallic Chemistry East China University of Science and Technology Shanghai 200237 Chinah Analytical Center and the Key Laboratory of Education Ministry for Optics and Magnetic Resonance Spectroscopy East China Normal University Shanghai 200062 China

Complexes （R^1Cp）（R^2Ind）ZrCl2, the catalysts previously reported active for ethylene polymerization showed high activity in ethylene/1-hexene copolymerization and propylene polymerization in the presence of MAO. The content of 1-hexene in copolymers ranged from 1.2% to 3.2%. In propylene polymerization the complex 1 showed the highest activity, up to 1.2×10^6 g of polypropylene per mol of catalyst per hour. Based on the analysis of NMR spectral data, the relationships between complex structures and polymerization results were explored.

关键词： indenyl cyclopentadienyl zirconium ethylene 1-hexene propylene metallocene complex