检索结果-南通市图书馆

Numerical simulation on the microstress and microstrain of low Si-Mn-Nb dual-phase steel

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2010年第2期17卷 173-178页

作者： Hai-feng Dong Jing Li Yue Zhang Joongkeun Park Qing-xiang Yang State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 China State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology Taejon 350-701 Korea

According to the stress-strain curves of single-phase martensite and single-phase ferrite steels,whose compositions are similar to those of martensite and ferrite in low Si-Mn-Nb dual-phase steel,the stress-strain curve of the low Si-Mn-Nb dual-phase steel was simulated using the finite element method（FEM）.The simulated result was compared with the measured one and they fit closely with each other, which proves that the FE model is *** on the FE model,the microstress and microstrain of the dual-phase steel were analyzed. Meanwhile,the effective factors such as the volume fraction of martensite and the yield stress ratio between martensite and ferrite phases on the stress-strain curves of the dual-phase steel were simulated,*** simulated results indicate that for the low Si-Mn-Nb dual-phase steel, the maximum stress occurs in the martensite region,while the maximum strain occurs in the ferrite *** effect of the volume fraction of martensite（fm） and the yield stress ratio on the stress-strain curve of the dual-phase steel is small in the elastic part,while it is obvious in the plastic *** the plastic part of this curve,the strain decreases with the increase of f_M,while it decreases with the decrease of the yield stress ratio.

关键词： dual-phase steel microstress microstrain numerical simulation finite element method(FEM)

RESISTANCE OF METALS TO microstrain AND ITS INFLUENTIAL FACTORS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1990年第12期3卷 420-425页

作者： ZHANG Lining ZHU Ping ZHOU Jinyin Southeast University,Nanjing,China

The microstraining prior to yield of several common metallic materials has been *** resistances of metals to microstrain and to macroyield are believed to be based on different deformation mechanisms and to be changed in different *** influential factors upon the microstraining,such as heat treatment,prestrain,strain-aging and residual stress together with their mechanisms have been also discussed.

关键词： microstrain dislocation plastic deformation

Stacking Effects on Electron-Phonon Coupling in Layered Hybrid Perovskites via microstrain Manipulation

在线全文

学校读者我要写书评

暂无评论

Stacking Effects on Electron-Phonon Coupling in Layered Hybr...

Bi3+assisted luminescence in SrMoO_(4):Sm^(3+) red phosphors

第七届新型太阳能电池材料科学与技术学术研讨会

作者： Qin Du Cheng Zhu Qi Chen School of Materials Science & Engineering Beijing Institute of Technology

Organic-inorganic hybrid halide perovskites(ABX),especially layered 2 D perovskites,have been recognized as promising semiconductors due to their tunable crystal structure and the unique optoelectronic properties.A-site cations,as spacers,allow various metal halide assemblies,but the stacking pattern and the influence of their collective behavior on the properties of the resultant materials remain ***,the cation stacking effects in the 2 D perovskite single crystals,with the focus on the electron-phonon interaction is *** reveal the different photoluminescence from the surface region and the interior of the crystal,which is owing to the residual strain induced by A-site cation *** also examine the cation stacking effects on electron-phonon interaction,which is further employed to tailor the optoelectronic properties of the resultant 2 D *** reducing the microstrain,we reduce the electron-phonon coupling to improve the mobility and their stability against electric field in the corresponding *** study suggests a way to manipulate the optoelectronic properties in 2 D perovskite materials by rational design of cation stacking.

关键词： 2D perovskites single crystal stacking effect microstrain electron-phonon coupling

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Rare Earths 2021年第11期39卷 1336-1343,I0002页

作者： Vaibhav Chauhan Prashant Dixit Praveen C.Pandey Department of Physics Indian Institute of Technology(Banaras Hindu University)Varanasi221005UPIndia

In this paper,we report synthesis of pure SrMoO_(4),Sm^(3+)(1 at%-5 at%)doped SrMoO_(4)and Bi^(3+)(1 at%-3 at%)co-doped in 4 at%Sm^(3+)doped SrMoO_(4)(SrMoO_(4):4 Sm^(3+))phosphors by solution combustion *** X-ray diffraction(XRD)analysis reveals the tetragonal phase of all samples,also Bi^(3+)co-doping supports crystallite size growth and reduces lattice *** analysis of Sm^(3+)doped SrMoO_(4)ascertains a decrease in band gap and Bi^(3+)co-doping confirms the emergence of an absorbance peak at around 308 nm attributed to Bi^(3+)energy ***(PL)analysis ascertains an increase in emission peaks for Sm^(3+)doped SrMoO_(4)up to 4%concentration,which are attributed to an electron transition from 4 G5/2 to 6 HJ(J=5/2,7/2,9/2,and 11/2)energy levels of Sm^(3+)*** have explained the effects of Bi^(3+)co-doping on the luminescence of Sm^(3+)doped SrMoO_(4).The reduced microstrain and increased crystallinity of the phosphors as a result of Bi^(3+)co-doping and their correlation with the luminescence of Sm^(3+)ions are discussed.

关键词： SrMoO_(4):Sm^(3+) Bismuth ion Photoluminescence Absorption study Crystallinity microstrain

Characterization of Different Surface States and Its Effects on the Oxidation Behaviours of Alloy 690TT

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2012年第4期28卷 353-361页

作者： Zhiming Zhang Jianqiu Wang En-Hou Han Wei Ke _TState Key Laboratory for Corrosion and Protection Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Alloy 690TT samples with four kinds of surface states were prepared： 1） ground to 400 grit; 2） ground to 1500 grit; 3） mechanically polished （MP） and 4） electro-polished （EP）. The surface morphologies and the surface skin layers＇ microstructures of these samples were characterized systematically using various methods and the effects of surface states on the oxidation behaviours of Alloy 690TT were also discussed. The results showed that surface roughness and micro-hardness decreased gradually from the ground to EP surfaces. The grains in the near-surface layers of the ground and MP surfaces had been refined and the residual strains were also very high. The dislocations on the ground surfaces were mainly parallel dislocation lines. The thickness of the superficial cold-worked layers decreased gradually from the ground surfaces to polished surfaces. The oxide morphologies and oxidation rate depended greatly on the surface states of samples. Cold-working by grinding treatments could benefit the outward diffusion of metallic atoms and the nucleation of surface oxides and then accelerate the growth of surface oxide films.

关键词： Alloy 690TT Surface states Cold-worked layer microstrain Grain refinement