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solar light assisted photocatalysis of water using a zinc oxide semiconductor

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Journal of semiconductors 2013年第4期34卷 11-14页

作者： s.s.shinde c.H.Bhosale K.y.Rajpure Electrochemical Materials Laboratory Department of PhysicsShivaji UniversityKolhapur 416004MaharashtraIndia

The photocatalytic decomposition of an eco-persistent AO7 dye with sunlight in an oxygenated aque- ous suspension has been studied under a nano-crystalline hexagonal ZnO photocatalyst. The effect of substrate temperature on the structural, morphological and photoactive properties has been investigated. The degradation of the AO7 dye is achieved using a photoelectrochemical reactor module equipped with ZnO synthesized electrodes. Kinetic parameters have been investigated in terms of a first order rate equation. The rate constant for this hetero- geneous photocatalysis was evaluated as a function of the initial concentration of original species. A substantial reduction in AO7 dye is achieved as analyzed from cOD and TOc studies. The mechanism for the degradation could be explained on the basis of the Langmuir-Hinshelwood mechanism.

关键词： zinc oxide chemical kinetics photoelectrocatalysis organic species sunlight

comparison of microstructure and mechanical behavior of Ti-35Nb manufactured by laser powder bed fusion from elemental powder mixture and prealloyed powder

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Journal of Materials science & Technology 2022年第10期105卷 1-16页

作者： J.c.Wang y.J.Liu s.X.Liang y.s.Zhang L.Q.Wang T.B.sercombe L.c.Zhang school of Engineering Edith Cowan University270 Joondalup DriveJoondalupPerthWA 6027Australia school of Engineering M050The University of Western Australia35 Stirling HighwayCrawleyPerthWA 6009Australia Northwest Institute for Nonferrous Metal Research Xi’an 710016China state Key Laboratory of Metal Matrix composites School of Material Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Although different types of powder feedstock are used for additive manufacturing via laser powder bed fusion(L-PBF),limited work has attempted to directly compare the microstructure and mechanical behavior of components manufactured from those powder *** work investigated the microstructure,phase composition,melt pool morphology,and mechanical properties of a prealloyed Ti-35Nb alloy manufactured using L-PBF and compared these to their counterparts produced from elemental powder *** samples manufactured from the powder mixture are composed of randomly distributed undissolved Nb in theα/βmatrix,resulting from the unstable melt pool during the melting of the powder *** contrast,parts produced from prealloyed powder display a homogeneous microstructure withβandαphases,owing to the full melting of prealloyed powder,therefore,a more stable melt pool to achieve a homogeneous *** Ti-35Nb manufactured from prealloyed powder exhibits large tensile ductility(about 10 times that of the counterparts using mixed powder),attributed to the high homogeneity in microstructure and chemical composition,strong interface bonding,relatively low oxygen content,and the existence of a large amount ofβ*** work sheds insights into understanding the effect of powder feedstock on the melt pool stability therefore the microstructure and mechanical behavior of the resultant parts.

关键词： Titanium-niobium Powder bed fusion Additive manufacturing Melt pool stability Microstructure Mechanical properties

Microstructural Evolution of Infrared Brazed cP-Ti Using Ti-cu-Ni Brazes

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Journal of Materials science & Technology 2011年第2期27卷 131-138页

作者： c.T.chang T.y.yeh R.K.shiue c.s.chang Department of Mechanical Engineering National Hualien Industrial Vocational Senior High SchoolHualien 970TaiwanChina Department of Materials science and Engineering National Taiwan UniversityTaipei 106TaiwanChina Engineered Materials solutions 39 Perry AvenueMS 4-1AttleboroMA 02703-2410USA

Microstructural evolution of infrared vacuum brazed cP-Ti using two Ti-based braze alloys,Ti-15cu-15Ni and Ti-15cu-25Ni,has been *** infrared brazed joint consisted of eutectic Ti 2 cu/Ti 2 Ni intermetallic compounds and Ti-rich *** eutectic Ti 2 cu/Ti 2 Ni intermetallic compounds disappeared from the joint after being annealed at 900 c for 1 *** contrast,the depletion rate of both cu and Ni from the braze alloy into cP-Ti substrate at 750 c annealing was greatly decreased as compared with that annealed at 900 *** Ti 2 cu/Ti 2 Ni phases were observed even if the specimen was annealed at 750 c for 15 *** the Ni content of the Ti-15cu-25Ni braze alloy is much higher than that of the Ti-15cu-15Ni alloy,the amount of eutectic Ti 2 cu/Ti 2 Ni phases in Ti-15cu-25Ni brazed joint is more than that in Ti-15ci-15Ni brazed ***,similar microstructural evolution can be obtained from the infrared brazed joint annealed at various temperatures and/or time for both filler metals.

关键词： Infrared Brazing cP-Ti Ti-cu-Ni fillers Microstructure

Multiple ballistic impacts on 2024-T4 aluminum alloy by spheres:Experiments and modelling

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Journal of Materials science & Technology 2021年第35期94卷 164-174页

作者： J.c.cheng s.P.Zhao D.Fan H.W.chai s.J.ye c.Li s.N.Luo y.cai J.y.Huang school of Materials science and Engineering Southwest Jiaotong UniversityChengduSichuanP.R.China The Peac Institute of Multiscale sciences ChengduSichuanP.R.China

Multiple ballistic impacts are carried out on a 2024-T4 aluminum alloy by spherical steel projectiles(5-mm diameter)at~400 m s^(-1),to investigate its dynamic deformation and *** ballistic impact process is captured with high-speed *** samples are characterized with optical imaging,three-dimensional laser scanning,microhardness testing and electron backscatter *** increasing number of impacts,crater diameter increases slightly,but crater depth and crater volume increase significantly,and strain accumulation leads to microhardness increase *** parameters all follow power-law relations with the number of ***-like deformation bands and macroscopic deformation twins are produced by impact as a result of spontaneous dislocation self-pinning under high strain rate,large shear *** multiple impacts,shear strain accumulation in the arc-shaped region of the crater induces deformation twinning when it exceeds a critical value(~1.1-1.6).It is highly possible that the deformation twins are related to deformation bands,since they both share one set of the{111}pole with the initial matrix grain.A finite element method model is optimized to reproduce experimental observations and interpret deformation mechanisms.

关键词： 2024Al-T4 alloy Multiple impacts Twin-like deformation band Deformation twinning Finite element method

Effect of Re Addition and Withdrawal Rate on the solidification Behavior of Directionally solidified superalloy AM3

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Journal of Materials science & Technology 2011年第2期27卷 101-106页

作者： F.Long y.s.yoo s.M.seo T.Jin Z.Q.Hu c.y.Jo Institute of Metal Research Chinese Academy of SciencesShenyang 110016China High Temperature Materials Laboratory Korea Institute of Materials Sciences66 Sangnam-dongChangwonKyungunamKorea

The influence of Re addition and withdrawal rate on the solidification behavior of the first generation single crystal superalloy AM3 was investigated by directional solidification and quenching *** primary dendrite arm spacing and eutectic volume fraction were measured from directionally solidified superalloy AM3 with different Re *** is found that the primary dendrite arm spacing is determined by the withdrawal rate,and Re does not influence on the *** eutectic fraction increases with increasing Re *** coeffcients of alloying elements were investigated with energy-dispersive X-ray spectrometry（EDs） *** data was submitted to a statistical treatment to establish the solidification path,and the partition coeficients were measured by fitting the curve with a modified scheil *** is shown that the addition of Re results in bigger microsegregation of alloying elements in directionally solidified AM3 superalloy.

关键词： superalloy AM3 Re addation Directional solidification

cracking evolution behaviors of lightweight materials based on in situ synchrotron X-ray tomography： A review

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Frontiers of Mechanical Engineering 2018年第4期13卷 461-481页

作者： y. Luo s. c. Wu y. N. Hu y. N. Fu state Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China shanghai synchrotron Radiation Facility Shanghai 201204 China

Damage accumulation and failure behaviors are crucial concerns during the design and service of a critical component, leading researchers and engineers to thoroughly identifying the crack evolution. Third-generation synchrotron radiation X-ray computed microtomo- graphy can be used to detect the inner damage evolution of a large-density material or component. This paper provides a brief review of studying the crack initiation and propagation inside lightweight materials with advanced synchrotron three-dimensional （3D） X-ray imaging, such as aluminum materials. Various damage modes under both static and dynamic loading are elucidated for pure aluminum, aluminum alloy matrix, aluminum alloy metal matrix composite, and aluminum alloy welded joint. For aluminum alloy matrix, metallurgical defects （porosity, void, inclusion, precipitate, etc.） or artificial defects （notch, scratch, pit, etc.） strongly affect the crack initiation and propagation. For aluminum alloy metal matrix composites, the fracture occurs either from the particle debonding or voids at the particle/matrix interface, and the void evolution is closely related with fatigued cycles. For the hybrid laser welded aluminum alloy, fatigue cracks usually initiate from gas pores located at the surface or sub-surface and gradually propagate to a quarter ellipse or a typical semi-ellipse profile.

关键词： fatigue crack initiation and growth fatigue damage mechanism damage tolerance defect characterization laser welded aluminum alloys

Physical properties of spray deposited cdTe thin films:PEc performance

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Journal of semiconductors 2011年第3期32卷 10-16页

作者： V.M.Nikale s.s.shinde c.H.Bhosale K.y.Rajpure Electrochemical Materials Laboratory Department of PhysicsShivaji University

p-cdTe thin films were prepared by spray pyrolysis under different ambient conditions and characterized using photoelectrochemical（PEc）,X-ray diffraction（XRD）,scanning electron microscopy,energy-dispersive analysis by X-ray（EDAX）,and optical transmission *** different preparative parameters viz solution pH, solution quantity,substrate temperature and solution concentration have been optimized by the PEc technique in order to get good-quality photosensitive *** analysis shows the polycrystalline nature of the film,having cubic structure with strong（111） *** reveal that grains are uniformly distributed over the surface of the substrate indicating the well-defined growth of polycrystalline cdTe thin *** EDAX study for the sample deposited at optimized preparative parameters shows the nearly stoichiometric cd：Te *** absorption shows the presence of direct transition with band gap energy of 1.5 *** films exhibit the highest photocurrent of 2.3 mA,a photovoltage of 462 mV,a 0.48 fill factor and 3.4%efficiency for the optimized preparative parameters.

关键词： cdTe PEc temperature concentration structure morphology composition optical

semiconducting properties of aluminum-doped ZnO thin films grown by spray pyrolysis technique

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Journal of semiconductors 2015年第3期36卷 23-28页

作者： M.A.Mahadik y.M.Hunge s.s.shinde K.y.Rajpure c.H.Bhosale Electrochemical Materials Laboratory Department of Physics Shivaji University

Highly transparent and preferential c-axis oriented nanocrystalline undoped and A1 doped zinc oxide （AZO） thin films have been deposited onto amorphous glass substrate by spray pyrolysis. The XRD studies reveal that AZO with a hexagonal （wurtzite） crystal structure having （002） preferred orientation is formed. The atomic force microscope （AFM） shows uniform surface topography. The optical band gap values of undoped and AZO thin films were changed from 3.34 to 3.35 eV. The band gap energy and photoluminescence are found to depend on the Al doping. Thermoelectric power measurement shows film having n-type in nature. Dielectric constant and loss （tan δ） were found to be frequency dependent. Interparticle interactions in the deposited films are studied by complex impendence spectroscopy.

关键词： aluminum zinc oxide structural morphological and dielectrical properties

Analytical modeling of effect of interlayer on effective moduli of layered graphene-polymer nanocomposites

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Journal of Materials science & Technology 2017年第8期33卷 827-833页

作者： c.c.Roach y.c.Lu Department of Mechanical Engineering University of KentuckyLexingtonKY 40506-0503USA

Nanocomposites enhanced with two-dimensional, layered graphene fillers are a new class of engineering materials that exhibit superior properties and characteristics to composites with conventional ***, the roles of ＂interlayers＂ in layered graphene fillers have yet to be fully explored. This paper examines the effect of interlayers on mechanical properties of layered graphene polymer *** an effective filler, the fundamental properties（in-plane young＇s modulus E（L1）, out-of-plane young＇s modulus E（L2）; shear modulus G（L12）, major Poisson＇s ratio V（L12）） of the layered graphene were computed by using the Arridge＇s lamellar model. The effects of interlayers on effective moduli of layered graphene epoxy composites were examined through the Tandon-Weng model. The properties of the interlayer show noticeable impact on elastic properties of the composites, particular the out-of-plane properties（young＇s modulus E2 and shear modulus G（12））. The interlayer spacing is seen to have much great influence on properties of the composites. As the interlayer spacing increases from 0.34 nm to 2 nm, all elastic properties of the composites have been greatly decreased.

关键词： Interlayer Layered graphene Nanocomposite Effective moduli