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ExPERIMENTAL INVESTIGATION AND THERMODyNAMIC CALCULATION ON PHASE PRECIPITATION OF INCONEL 740

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Acta Metallurgica Sinica(English Letters) 2006年第6期19卷 425-431页

作者： S.Q.Zhao y.jiang j.x.Dong x.S.xie Department of Physics Ningxia UniversityYinchuan 750021China Department of Materials Science The Northwest Second Nationalities InstituteYinchuan 750021China High Temperature Materials Research Laboratories University of Science and Technology BeijingBeijing 100083China

A novel nickel-based superalloy INCONEL 740 was under development for application in ultra-supercritical superheater tubers above 750℃. The precipitation behaviors of η phase and γ' particles of the alloy were investigated through experimental study and phase computation. Experimental results showed that η phase formed a Widmanst?tten pattern structure following long-term exposure at elevated temperatures and that the coarsening of γ' particle follows a cube rate law:r-3 ∝ t. Thermodynamic calculation results showed that Al and Ti had an important effect on the precipitation behavior of γ' andη phases. Two suggested novel modified alloys, wherein the Al and Ti contents were modified, were designed and melted for the experimental study. The preliminary results indicated that the modified alloys exhibited higher structural stability following long-term exposure at 750℃ till 5000h.

关键词： superalloy INCONEL 740 precipitate thermodynamic calculation

STUDy OF DyNAMIC RECRySTALLIZATION OF LOW CARBON STEEL IN THIN SLAB CONTINUOUS ROLLING PROCESS

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Acta Metallurgica Sinica(English Letters) 2006年第4期19卷 265-270页

作者： x.K. Liang x.j. Sun Q.y. Liu H. Dong State Key Laboratory of Advanced Steel Processes and Products Central Iron and Steel Research Institute Beijing 100081 China

Combined with the technological characteristics of thin slab continuous rolling process （TSCR）, dynamic recrystallization of an extremely coarse austenite of low carbon steel is studied by Thermecmaster-Z hot simulator. By the analysis of true stress-strain curves and the observation of microstructures at different deformation stages, the critical stress and critical strain are determined under different deformation conditions. The effect of Z parameter on dynamic recrystallization of coarse austenite is studied. The microstructure evolution in real production is also discussed.

关键词： TSCR (thin slab continuous rolling process) coarse austenite dynamic recrystallization

STUDy ON PREPARATION, COMPLEx PERMITTIVITy,PERMEABILITy AND MICROWAVE PROPERTIES OF BaZnzCo(2-z)Fe16O27/SiO2 MICROCRySTALLINE GLASS CERAMICS

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Acta Metallurgica Sinica(English Letters) 2003年第6期16卷 421-427页

作者： H.j.Zhang x.L.jia x.y.o L.y.Zhang HighTemperatureCeramicsInstitute ZhengzhouUniversityZhengzhou450052China FunctionalMaterialsResearchLaboratory TongjiUniversityShanghai200092China

BaZnzCo2-zFe16O27/SiO2 microcrystalline glass ceramics with Z=0.0, 0.5, 0.8 and 1.1 were prepared at temperature 1200℃ for 5h by citrate sol-gel process. The complex dielectric constant and complex permeability of BaZnzCo2-zFe16 O27/SiO2-paraffin wax composites had been measured. Both the complex dielectric constant and dielectric loss exhibit almost no variation with frequency in 0.1-6.0GHz. The real part of permeability decreases with increasing frequency for all samples, and the imaginary part of permeability exhibits a clear resonance peak at 1.44GHz for Co2 W/SiO2, 1.32GHz for Zn0.5Co1.5 W/SiO2, 1.20GHz for Zn0.8Co1.2W/SiO2, and 1.08GHz for Zn1.1 Co0.9 W/SiO2. It is also showed that the content of zinc has a close effect on the magnetic properties of BaZnzCo2-zFe16O27/SiO2 microcrystalline glass ceramics, the greater the zinc content, the higher the values of imaginary part of permeability and magnetic loss.

关键词： BaZnz Co2-zFe16O27/SiO2 microcrystalline glass ceramics,sol-gel microwave property

Stabilizing nanograined Fe-Cr alloy by Si-assisted grain boundary segregation

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journal of Materials Science & Technology 2023年第3期134卷 223-233页

作者： x.F.xu x.y.Li B.Zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China

Intentional solute segregation at grain boundary(GB)can effectively stabilize the nanograined alloys by reducing the excess energy and mobility of GB,but it usually works for binary alloys with sufficient GB segregation ***,we found that the segregation of Cr can be enhanced in a nanostruc-tured Fe-8Cr alloy with insufficient GB segregation tendency through the interaction of another solute Si(1.0 wt.%).After surface mechanical grinding treatment and subsequent annealing,the nanograined Fe-8Cr-1Si is more thermally stable than the nanograined Fe-8Cr,which is mainly attributed to the Si-enhanced Cr segregation as observed by Super-x energy-dispersive x-ray spectroscopy(EDS)mapping *** the grain refinement to nanoscale,the thermal stability is further improved due to the in-crease of Cr content at GBs and the precipitates formed at appropriate high *** present finding provides guidance for the development of advanced nanostructured ternary alloys.

关键词： Segregation Grain boundary Fe-Cr-Si alloy Nanocrystalline Thermal stability

Improved mechanical properties and strengthening mechanism with the altered precipitate orientation in magnesium alloys

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journal of Magnesium and Alloys 2022年第5期10卷 1256-1267页

作者： y.j.Wan y.Zeng y.C.Dou D.C.Hu x.y.Qian Q.Zeng K.x.Sun G.F.Quan Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Material Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China College of Materials Science and Engineering Sichuan University of Science and EngineeringZigong 643000China Department of Materials The University of ManchesterOxford RoadManchester M139PLUnited Kingdom

Aging prior to twinning deformation was proposed to alter the precipitate orientation of the plate-shapedβ-MgAlfrom(0002)basal planes(named basal plates)to■prismatic planes(named prismatic plates)in AZ31 Mg *** experimental results showed that the compressive yield strength(CyS)of the sample containing prismatic plates increased 40 MPa and the compression ratio raised by 22%compared to that containing basal *** underlying strengthening mechanism was analyzed via a yield strengthen(yS)model with a function of grain size,precipitate characters(size,oritention,fraction)and Schmid factor(SF).It revealed that the improvement of CyS was mainly attributed to the altered precipitate orientation and refined grain size produced by twinning ***,the prismatic plates always have a stronger hardening effect on basal slip than basal plates under the same varites of precipitate diameter and ***,the decreased CRSS ratio of prismatic slip to basal slip revealed that the activity of non-basal slip in Mg alloy might be *** activated slip systems provided more mobile dislocations,contributing to the large compression ratio of the Mg rolled sheet with prismatic plates.

关键词： Precipitate orientation Precipitation strengthening Grain boundary strengthening yield strength model

A STUDy OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

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Acta Metallurgica Sinica(English Letters) 2007年第1期20卷 27-34页

作者： x.B. Li y.Q. xie y.Z. Nie H.j. Peng H.j. Tao F.x. yu College of Materials Science and Engineering Central South University Changsha 410083 China

On the basis of energy and shape method for the determination of the valence bond （ VB ） structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is ec^29907. （sc^0.4980 ＋ dc^2.4927） ef^1.0098 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.

关键词： valence bond structure temperature titanium

Cadmium sulfide cage photocatalysis coupled electroactive biofilm for synergistic promotion of tetracycline degradation and electricity production

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journal of Materials Science & Technology 2023年第35期166卷 86-97页

作者： Z.S.yuan j.x.Zou x.L.Zhao j.y.Shi C.S.Guo M.yan School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China

Tetracycline(TC)as a common broad-spectrum antibiotic,has been frequently detected in soil and sur-face *** becomes a great threat to the ecological ***,a device of photocatalysis as-sisted microbial fuel cell(photo-MFC)was constructed for TC degradation and energy *** this photo-MFC,cadmium sulfide(CdS)cage photocatalysis can degrade most of TC in a short *** the Co_(3)O_(4)@C-CC(carbonization and calcination of the ZIF-67 precursor in-situ grown on the carbon cloth(CC))bioanode degrades the rest of TC as well as the photocatalytic products,thus improving the *** co-existence of photocatalysis with bioanode changes the microbial community structure of the *** dominant phylum is Geobacter(60.2%)in normal MFC while that in photo-MFC are Pro-teobacteria(43.5%)and Geobacter(33.2%).Therefore,the synergistic effect of photocatalytic degradation and biodegradation achieves a chemical oxygen demand(COD)removal of 98.6%,which is higher than that of normal MFC(77.6%)or single CdS cage photocatalysis(23.8%).In addition,the photogenerated electrons can be transferred to the cathode,which reduces their combination with holes and increases the electricity generation of MFC,achieving a maximum power density of 3.37 W/m^(2).After degradation,the effluent with 200 mg L^(−1) TC exhibits no visible ***,electrochemical test,finite-difference time-domain(FDTD),density functional theory(DFT)calculation and the free radical trapping experiments verify the possible mechanisms of photocatalytic degradation in this *** strat-egy paves a new way for low energy consumption removal and energy recovery of organic pollutants.

关键词： Photo-MFC CdS cage Tetracycline degradation Mineralization Electricity production

Evaluation of carbon-based nanosorbents synthesised by ethylene decomposition on stainless steel substrates as potential sequestrating materials for nickel ions in aqueous solution

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journal of Environmental Sciences 2012年第9期24卷 1559-1568页

作者： x.j.Lee L.y.Lee L.P.y.Foo D.G.Hassell Department of Chemical and Environmental Engineering University of Nottingham Malaysia CampusJalan Broga43500 SemenyihSelangor Darul EhsanMalaysia.

The present work covers the preparation of carbon-based nanosorbents by ethylene decomposition on stainless steel mesh without the use of external catalyst for the treatment of water containing nickel ions （Ni2＋）. The reaction temperature was varied from 650 to 850℃, while reaction time and ethylene to nitrogen flow ratio were maintained at 30 rain and 1：1 cma/min, respectively. Results show that nanosorbents synthesised at a reaction temperature of 650℃ had the smallest average diameter （75 nm）, largest BET surface area （68.95 m2/g） and least amount of impurity （0.98 wt.% Fe）. A series of batch sorption tests were performed to evaluate the effects of initial pH, initial metal concentration and contact time on Ni2~ removal by the nanosorbents. The equilibrium data fitted well to Freundlich isotherm. The kinetic data were best correlated to a pseudo second-order model indicating that the process was of chemisorption type. Further analysis by the Boyd kinetic model revealed that boundary layer diffusion was the controlling step. This primary study suggests that the prepared material with Freundiich constants compared well with those in the literature, is a promising sorbent for the sequestration of Ni2＋ in aqueous solutions.

关键词： adsorption nanosorbent nickel ions isotherms kinetics

Sample selection for models to represent ceramic cores fabricated by stereolithography three-dimensional printing

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journal of Materials Science & Technology 2022年第26期121卷 117-123页

作者： x.L.An j.j.Liang j.G.Li j.W.Chen y.Z.Zhou x.F.Sun School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Space Manufacturing Technology(CAS Key Lab) Beijing 100094China

Ceramic cores with good chemical stability and moderate mechanical properties near casting temperatures of 1550℃ for example are used for the manufacturing of internal structures of hollow blades,requiring complex structures and high precision[1–3].However,traditional preparation method based on investment casting is tedious,requiring not only long production cycles but also high cost[4].

关键词： investment printing ceramic