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Mechanism of High Temperature Deformation in Cast Ti46Al8.5Nb0.2W Alloy

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Journal of university of science and technology beijing 2001年第4期8卷 290-294页

作者： Zicheng Liu, junpin lin, yanli wang, zhi lin, Guoliang chen State key laboratory for advanced metals and materials, university of science and technology beijing, beijing 100083, china Univ Sci & Technol beijing State Key Lab Adv Met & Mat Beijing 100083 Peoples R China

Compression tests A ere conducted in the two phase Ti46Al8.5Nb0.2W alloy with a cast microstructure under the strain rates ranging from 2x10(-5) s(-1) to 10(-2) s(-1) at temperatures ranging front 900degreesC to 1100degreesC. It was found that there exist approximately linear relationships between the flow stress and the logarithm of strain rate at different temperatures. The strain rate dependence was analzed by the thermal activation theory and dislocation climbing is regarded as the controlling mechanism during high temperature compression tests.

关键词： Ti46%Al8.5%Nb0.2%W high temperature compression strain rate dislocation climbing

Effect of heat treatment on mechanical properties of heavily cold-rolled Fe-6.5wt%Si alloy sheet

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science china(Technological sciences) 2010年第4期53卷 1008-1011页

作者： LIANG YongFeng,YE Feng,lin junpin,wang yanli,ZHANG LaiQi & chen GuoLiang State key laboratory for advanced metals and materials,university of science and technology beijing,beijing 100083,china 1. State key laboratory for advanced metals and materials University of Science and Technology Beijing Beijing 100083 China

Fe-6.5wt%Si alloy has excellent soft magnetic properties,but it is hard to be cold-rolled due to appearance of ordered phases in this *** this paper we report that ultra thin Fe-6.5wt%Si sheet of 0.05 mm thick was obtained by heavily cold *** means of optical microscope,micro-hardness indenter,instron,SEM and X-ray diffraction,the effect of heat treatment on mechanical properties of this alloy sheet was *** heavily cold-rolled sheet exhibits some extent of *** ultimate tensile strength reaches 1.93 *** heat treatment,micro-hardness is decreased and the ductility is lost,especially at temperature above 650℃ when recrystallization takes *** reason for decreasing the ductility lies in the ordered DO3 phase transformation.

关键词： Fe-6.5wt%Si alloy cold rolling heat treatment microstructure mechanical properties

MEAM Potential with Angular Dependence for TiAl

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Rare metals 2001年第1期20卷 13-17页

作者： Xiaodong Ni, Xitao wang, Guoliang chen (Physics Department, university of science and technology beijing, beijing 100083, china State key laboratory for advanced metals and materials, university of science and technology beijing, beijing 100083, china) Univ Sci & Technol beijing Dept Phys Beijing 100083 Peoples R China Univ Sci & Technol beijing State Key Lab Adv Met & Mat Beijing 100083 Peoples R China

The modified embedded atom method (MEAM) is an empirical extension of the embedded atom method (EAM) that includes angular forces. By fitted to the lattice constants, the cohesive energy, the APE (anti-phase boundary) energy, and the vacancy formation energy of TiAl, an accurate MEAM potential is obtained for the TiAl system with L10 structure. The calculation results of the properties of TiAl are in good agreement with experiments and the results of first principle (F.P.) calculations.

关键词： embedded atom method TiAl alloy angular dependence potential intermetallics

Characterization of γ′ precipitates in a nickel base superalloy quenching from aging temperature at different rates

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Rare metals 2010年第2期29卷 204-208页

作者： LI Hongyu, SONG Xiping, wang yanli, and chen Guoliang State key Lab for advanced metals and materials, university of science and technology beijing, beijing 100083, china State key Lab for advanced metals and materials University of Science and Technology Beijing

The characteristics of γ′ precipitates in a superalloy quenched from 1050°C at different rates were investigated using field emission scanning electron microscope（FESEM）.When quenched from 1050°C, the size of primary aging γ′ precipitates has a small increase in the specimens that experienced iced-brine-quenching, oil-quenching, and air-cooling-quenching conditions and a drastic increase in the specimen that experienced a furnace-cooling-quenching *** cooling γ′ precipitates have unimodal distributions after quenching at the air-cooling rate and bimodal distributions after quenching at the furnace-cooling rate, but there are not these distributions in the specimens that experienced iced-brine-quenching and oil-quenching *** aging at 760°C, the size of primary aging γ′ precipitates appears unaffected in the specimens that experienced iced-brine-quenching, oil-quenching, and air-cooling-quenching ***, it has a drastic increase in the specimen that experienced a furnace-cooling-quenching condition, and it is interesting that the bigger cooling γ′ precipitates have a coalescence and octodendritic *** microhardness study indicates that the hardness has no variation in the specimens that experienced iced-brine-quenching, oil-quenching, and air-cooling-quenching conditions and has a drastic decrease in the specimens that experienced a furnace-cooling-quenching condition and obtains the minimum microhardness value 390.8 HV.

关键词： superalloys precipitates quenching rate microhardness

Homogenization treatment of high Nb containing TiAl alloys with as-cast and as-forged microstructures

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Rare metals 2008年第2期27卷 181-186页

作者： XU Zhengfang XU Xiangjun lin junpin ZHANG Yong wang yanli lin zhi chen Guoliang State key laboratory for advanced metals and materials University of Science and Technology Beijing Beijing 100083 China

The effect of heat treatment on the microstructure evolution of a high Nb containing TiAl alloy has been studied. The results indicate that β-segregation, β-segregation and S-segregation in the as-cast and as-forged alloys can be effectively eliminated at the temperature above Tα （1350-1400℃） for long holding time （12-24 h） and the full lamellar （FL） microstructure is gained. For the two alloys, the lamellar colony sizes are 120 μm and 2000 μm, respectively after heat treatment at 1400℃ for 12 h. Meanwhile, the sizes are 210 μm and 3000 μm, respectively at 1350℃ for 24 h. To get a fine homogenous microstructure, the primary as-cast alloy is first subjected to preheat treatment for eliminating the segregations. After the preheat treatment, the ailoy is processed by the multi-step canned forging to attain the microstructure with fine grain size.

关键词： TiAl-based alloy Nb-containing FL microstructure heat treatment rnicrosegregation

Diffusion behavior of Nb element in high Nb containing TiAl Alloys by reactive hot pressing

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Rare metals 2006年第4期25卷 349-354页

作者： wang Yanhang lin junpin HE Yuehui wang yanli chen Guoliang State key laboratory for advanced metals and materials University of Science and Technology Beijing Beijing 100083 China State key laboratory for Powder Metallurgy Central South University Changsha 410083 China

Diffusion behavior of Nb in elemental powder metallurgy high Nb containing TiAl alloys was investigated. The results show that Nb element dissolves into the matrix by diffusion. Pore nests are formed in situ after Nb diffusion. With the increase in hot pressing temperature, the diffusion of Nb will be more sufficient, and the microstructure is more homogeneous. Nb element diffuses completely at 1400℃. Meanwhile, compression deformation and agglomeration phenomena of pores are observed in some pore nests. Hot isostatic pressing （HIP） treatment can only efficiently decrease but not eliminate porosity completely.

关键词： powder metallurgy TiAl-based alloy hot pressing diffusion hot isostatic pressing

The adsorption effect of aquaculture residual feed on heavy metals and its impact on microbial metabolism of feed

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Ecological Processes 2024年第2期13卷 246-259页

作者： Sufeng wang Zijng wang Wen Zhang Jingshan Li Mingyang lin Li chen State key laboratory of Metastable materials science and technology Hebei Key Laboratory of Heavy Metal Deep-Remediation in Water and Resource Reuse Yanshan University key laboratory of Pollution Exposure and Health Intervention of Zhejiang Province College of Biology and Environmental EngineeringZhejiang Shuren University Hebei Ocean & Fisheries science Research Institute

Background Intensive and large-scale aquaculture has a high biological density, and a large amount of artificial feed must be provided. As a result, residual feed would be discharged into natural water bodies with water exchange. Due to heavy metal pollution in surface water, residual feed may adsorb heavy metals in the water, affecting the subsequent microbial degradation of feed and the restoration of the water environment. The combined ecological impacts of these two types of pollution urgently need to be *** This study explored the adsorption effect of residual feed on heavy metals and its impact on microbial degradation of residual feed. The results showed that both the insoluble component（mainly fiber, ash, and ether extract, abbreviated as FAE） and soluble component（soluble protein and starch） of the feed had adsorption effects on heavy metals. As the salinity increased, the adsorption capacity of Cu2+and Cd2+decreased, while the adsorption effect on Pb2+was not changed significantly. The adsorption of heavy metals by residual feed could affect the biological degradation of residual feed. The residual feed could adsorb heavy metals and bacterial cells simultaneously, forming FAE-B（bacteria）-S（starch）-Pr（protein）-metal adsorption complex. This adsorption effect could reduce the negative impact of heavy metals on microbial degradation of residual feed. The simulated degradation experiments in actual water bodies also confirmed this. However, the accumulation of heavy metals in residual feed may bring negative effects, such as being consumed by aquatic organisms and entering the food *** The results of this study provide a basis for the collection and centralized treatment of residual feed in aquaculture, as well as the control and remediation of residual feed pollution in natural water bodies.

关键词： Residual feed Adsorption complex Feed pollution Heavy metal

Honeycomb-like MoCo alloy on 3D nitrogen-doped porous graphene for efficient hydrogen evolution reaction

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Rare metals 2024年第3期43卷 1072-1082页

作者： lin-Ping wang Kuang Li Hua-Long Ding Le Xu chen Huang Jiao-Jiao Zhou Cong-TaoWen Pei-lin Zhang Wei-Wei wang Lu-Yang chen key laboratory for Ultrafine materials of Ministry of Education School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai200237China State key laboratory of High-Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai200050China State key laboratory of Chemical Engineering and School of Chemistry and Molecular Engineering East China University of Science and TechnologyShanghai200237China

An efficient electrocatalyst is indispensable to significantly reduce energy consumption and accelerate the conversion efficiency of water *** this work,the honeycomb-like porous MoCo alloy on nitrogen-doped three-dimensional(3D)porous graphene substrate(Mo_(0.3)Co_(0.7)@NPG)has been synthesized from the annealing of layered double hydroxide(MoCo-LDH@NPG).Especially,the Mo_(0.3)Co_(0.7)@NPG exhibits low hydrogen evolution overpotential of 75 mV(10 mA·cm^(-2))and a Tafel slope of 69.9 mV·dec^(-1),which can be attributed to highly conductive NPG substrate,the unique nanostructure and the synergistic effect of Mo and ***,the Mo_(0.3)Co_(0.7)@NPG can maintain the original morphology and high catalytic activity after 50-h stability *** work proposes a general strategy to synthesize a multi-element alloy on conductive substrates with high porosity for electrocatalytic reaction.

关键词： MoCo alloy Three-dimensional nitrogen-doped porous graphene Hydrogen evolution reaction(HER)

Coarsening behavior of γ' particles in a nickel-base superalloy

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Rare metals 2009年第2期28卷 197-201页

作者： Li, Hongyu Zuo, lingli Song, Xiping wang, yanli chen, Guoliang State key laboratory for advanced metals and materials University of Science and Technology Beijing Beijing 100083 China

The coarsening behavior of γ particles in a nickel-base superalloy FGH95 was investigated by means of experimental observations and growth kinetics calculations. The results show that when aging at 1000,1080 and 1140°C for different times,the relation of average particle size to time obeys the cube law ( a /2)3= kt,where k is 15.49 × 103,77.5 × 103 and 230.04 × 103 nm3/min,respectively. The particle size distributions are better fit to the LSW theoretical distributions when aging at 1000°C within 1440 min....

关键词： nickel-base superalloys γ particles coarsening behavior particle size distribution activation energy