检索结果-南通市图书馆

Journal of Materials Science & Technology 2021年第35期94卷 147-163页

作者： Mehran Golizadeh Francisca Mendez Martin Stefan Wurster Johann P.Mogeritsch Abdellah Kharicha Szilard Kolozsvári Christian Mitterer Robert Franz Department of Materials Science Montanuniversitat LeobenFranz Josef-Straβe 188700 LeobenAustria Erich Schmid Institute of Materials Science Austrian Academy of SciencesJahnstraβe 12.8700 LeobenAustria Department of Metallurgy Montanuniversitat LeobenFranz Josef-Straβe 188700 LeobenAustria Plansee Composite Materials GmbH Siebenbiirgerstraβe 2386983 Lechbruck am SeeCermany

A combination of both conventional and advanced high-resolution characterization techniques was applied to study the modified layers on the surface of three composite Al-Cr arc cathodes with identical nominal composition of Al-50 at.%Cr but varying powder grain *** results revealed that the modified layers consist mainly of metastable phases such as Cr solid solution,high temperature cubic Al8 Cr5,supersaturated Al solid solution,and icosahedral *** metastable phase formation indicates that high cooling rates were involved during the solidification of molten material produced in the arc craters during cathode spot *** average cooling rate was estimated to be 10^(6)K/s based on secondary dendrite arm spacing measurements and supporting phase-field based *** formation mechanisms of the modified layers are discussed based on the obtained results and the current literature.

关键词： Cathodic arc rapid solidification Quasicrystal Arc crater Macroparticle Phase-field simulation

rapid solidification OF HYPEREUTECTIC SILVER-COPPERALLOY IN DROP TUBE

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1999年第3期12卷 251-258页

作者： Wang, N. Wei, B. Northwestern Polytechnical Univ Xi'an China

The Ag-50wt%Cu hypereutectic alloy was solidified and investigated in a 3 m drop tube, and its nucleation and microstructure characteristics were explored also. The results showed that (1) with the decrease of droplet size, the structural morphology transforms from the dendrites with long trunk and thin short secondary arms to fine dendritic structures; (2) the dendritic growth is mainly controlled by solute diffusion within the whole undercooling regime, while the influence of thermal diffusion-controlled growth becomes stronger above a critical undercooling about 268 K; (3) the refinement of dendritic structure is caused by large amounts of nuclei within droplet; (4) when droplet diameter is smaller than 300 micron, the undercooling and growth velocity were estimated to be greater than 268 K and 290 mm/s respectively, while the solute trapping effect may occur.

关键词： Eutectics Morphology rapid solidification

rapid solidification of steel droplets with different carbon contents in drop tube

在线全文

学校读者我要写书评

暂无评论

China Foundry 2012年第1期9卷 20-23页

作者： Li Na Sha Minghong Xu Qian Zhang Shuang Li Shengli School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051China Tianjin Iron and Steel Group Co. LtdTianjin 300301China

rapid solidification is regarded as being an effective method to refine the microstructure and reduce or eliminate the segregation of alloying *** this study the microstructures of rapid solidified carbon steel droplets (cooled in silicone oil) with different C contents by drop tube processing were *** volumes of droplets were set to be 2 mm×2 mm×2 mm (TM) and 5 mm×5 mm×5 mm (FM).For most samples,the microstructures are nearly the same from the surface to the center *** microstructures of the FM samples with higher C content are much finer than those of the TM samples,which is the opposite of the situation with the lower C content *** distribution of C along the diameter of each sample was *** segregation of C was observed in TM samples with higher C contents while not in FM *** is regarded as relating to recalescence and the diffusion of C atoms during the solidification process.

关键词： rapid solidification carbon droplet drop tube

Microstructural evolution of Al-20Si-5Fe alloy during rapid solidification and hot consolidation

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2009年第6期28卷 639-645页

作者： M.Rajabi M.Vahidi A.Simchi P.Davami Department of Materials Science and Engineering Sharif University of Technology Institute for Nanoscience and Nanotechnology (INST) Sharif University of Technology

Al-20Si-5Fe melt was rapidly solidified into particles and ribbons and then consolidated to near full density by hot pressing at 400℃/250 MPa/1 h. According to the eutectic-growth and dendritic-growth velocity models, the solidification front velocity and the amount of undercooling were estimated for the particles with different sizes. Values of 0.43-1.2 cm/s and 15-28 K were obtained. The secondary dendrite arm spacing revealed a cooling rate of 6 × 10^5 K/s for the particles with an average size of 20 μm. solidification models for the ribbons yielded a cooling rate of 5 × 10^7 K/s. As a result of the higher cooling rate, the melt-spun ribbons exhibited considerable microstructural refinement and modification. The size of the primary silicon decreased from approximately 1μm to 30 nm while the formation of iron-containing intermetallic compounds was suppressed. Supersaturation of the aluminum matrix in an amount of-7 at.% Si was noticed from the XRD patterns During the hot consolidation process, coarsening of the primary silicon particles and precipitation of β-Al5FeSi phase were observed. Evaluation of the compressive strength and hardness of the alloy indicated an improvement in mechanical properties due to the microstructural modification.

关键词： Al-Si-Fe alloy rapid solidification cooling rate microstructure mechanical properties

Advantages of rapid solidification over casting of Mg-0.4Zn-1Y alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第7期12卷 2847-2862页

作者： Drahomír Dvorský Shin-Ichi Inoue Ayami Yoshida JiríKubásek Jan Duchon Esther de Prado Andrea Školáková Klára Hosová Petr Svora Yoshihito Kawamura Institute of Physics Czech Academy of SciencePragueNa Slovance 1999/218221 Praha 8Czechia Magnesium Research Center Kumamoto UniversityKumamoto2-39-1 Kurokami Chuo-ku Kumamoto860-8555 Japan Department of Metals and Corrosion Engineering Faculty of Chemical TechnologyUniversity of Chemistry and Technology PragueTechnická516628 Praha 6–DejviceCzechia

The Mg-Y-Zn magnesium alloy system is commonly recognized for its remarkable combination of high strength and ductility,achieved even with minimal amounts of alloying *** exceptional performance is attributed to its unique microstructure,which includes Long-Period Stacking Ordered(LPSO)phases or the distinctive microstructure derived from the LPSO phase,referred to as the Mille-Feuille structure(MFS).This study systematically compares the traditional ingot metallurgy method with the rapid solidification technique,coupled with diverse heat treatments and extrusion *** analyses reveal variations in the presence of LPSO phases,Mille-Feuille structure,and grain size,leading to divergent mechanical and corrosion *** rapid solidification approach stands out,ensuring superior mechanical properties alongside a reasonable corrosion rate.

关键词： rapid solidification LPSO Kink Extrusion Corrosion Ignition temperature

Dislocation mechanism of Ni_(47)Co_(53) alloy during rapid solidification

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2023年第6期32卷 410-419页

作者：刘云春梁永超陈茜张利马家君王蓓高廷红谢泉 Institute of Advanced Optoelectronic Materials and Technology School of Big Data and Information EngineeringGuizhou UniversityGuiyang 550025China

Dislocations and other atomic-level defects play a crucial role in determining the macroscopic properties of crystalline materials,but it is extremely difficult to observe the evolution of dislocations due to the limitations of the most advanced experimental ***,in this work,the rapid solidification processes of Ni_(47)Co_(53) alloy at five cooling rates are studied by molecular dynamics simulation,and the evolutions of their microstructures and dislocations are investigated as *** results show that face-centered cubic(FCC) structures are formed at the low cooling rate,and the crystalline and amorphous mixture appear at the critical cooling rate,and the amorphous are generated at the high cooling *** crystallization temperature and crystallinity decrease with cooling rate *** are few at the cooling rates of 1×10^(11) K/s,5×10^(12) K/s,and 1×10^(13) K/s,and they are most abundant at the cooling rates of 5×10^(11) K/s and1 × 10^(12) K/s,in which their dislocation line lengths are both almost *** appear a large number of dislocation reactions at both cooling rates,in which the interconversion between perfect and partial dislocations is *** dislocation reactions are more intense at the cooling rate of 5×10^(11) K/s,and the slip of some dislocations leads to the interconversion between FCC structure and hexagonal close packed(HCP) structure,which causes the twin boundaries(TBs) to *** FCC and HCP are in the same atomic layer,and dislocations are formed at the junction due to the existence of TBs at the cooling rate of 1 ×10^(12) K/*** present research is important in understanding the dislocation mechanism and its influence on crystal structure at atomic scales.

关键词： molecular dynamics simulation rapid solidification crystal structure dislocation interaction

Flow field simulation of the thin metal ribbon formed by twin-belt rapid solidification

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2008年第2期15卷 155-160页

作者： Yan Liu Jianxin Xie Feng Guo Cheng Zhou School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Liaoning Institute of Technology Jingzhou 121001 China

The flow field formed when an aluminum ribbon is produced by twin-belt rapid solidification is simulated with the solution algorithm （SOLA）-volume of fluid （VOF） method, and the influence of casting speed and cooling-belt velocity on the flow field is analyzed for a given ejection nozzle size. It has been found that the flow field can be filled well when the width of the ejection nozzle outlet is the same as that of the up slit of the cooling belt. When the ejection nozzle outlet is wider than the up slit of the cooling belt, the aluminum fluid can fill well if only the casting speed matches the cooling-belt velocity properly, otherwise under filling occurs in some areas in the cooling zone.

关键词： rapid solidification twin-belt method numerical simulation ribbon forming

mproved Hydrogen Storage Properties of Ti_(23)V_(40)Mn_(37)Alloy Doped with Zr_(7)Ni_(10) by rapid solidification

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2023年第7期36卷 1211-1219页

作者： Zhenyu Feng Hong Zhong Bin Yang Xin Li Shuangming Li State Key Laboratory of solidification Processing Northwestern Polytechnical UniversityXi’an710072China Inner Mongolia Metal Material Research Institute Yantai264003China School of Materials Engineering Xi’an Aeronautical UniversityXi’an710077China

As-cast and rapidly solidified Ti_(23)V_(40)Mn_(37)alloy doped with Zr_(7)Ni_(10) was synthesized by arc melting and *** microstructure,activation property,hydrogen absorption kinetics,and hydrogen absorption/desorption thermodynamics were investigated to evaluate a comprehensive hydrogen storage property of the *** preparation methods had a negligible effect on the lattice parameter of BCC and C14 Laves phases in the *** alloy prepared by melt-spinning showed an increased proportion of BCC phase,larger hydrogen absorption capacity,faster hydrogen absorption rate,and higher hydrogen absorption/desorption platform *** dehydriding enthalpy and endothermic peak temperature of the rapidly solidified alloy were 33.55±2.14 KJ/mol H_(2)and 526.2 K,respectively,which are smaller than those of the as-cast *** indicates the decreased hydride stability and improved hydrogen desorption *** contrast with the as-cast alloy,the rapidly solidified alloy showed a preferable comprehensive hydrogen storage property.

关键词： rapid solidification Microstructure Hydrogen absorption kinetics Hydrogen desorption property

Effects of rapid solidification on the microstructure and microhardness of a lead-free Sn-3.5Ag solder

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2006年第4期25卷 365-370页

作者： SHEN Jun LIU Yongchang Han Yajing GAO Houxiu College of Mechanical Engineering Chongqing University Chongqing 400044 China College of Materials Science and Engineering Tianjin University Tianjin 300072 China

A lead-free Sn-3.5Ag solder was prepared by rapid solidification technology. The high solidification rate, obtained by rapid cooling, promotes nucleation, and suppresses the growth of Ag3Sn intermetallic compounds （IMCs） in Ag-rich zone, yielding fine Ag3Sn nanoparticulates with spherical morphology in the matrix of the solder. The large amount of tough homogeneously-dispersed IMCs helps to improve the surface area per unit volume and obstructs the dislocation lines passing through the solder, which fits with the dispersion-strengthening theory. Hence, the rapidly-solidified Sn-3.5Ag solder exhibits a higher rnicrohardness when compared with a slowly-solidified Sn-3.5Ag solder.

关键词： lead-free solder nanoparticulate rapid solidification intermetallic compounds dispersion-strengthening effect

Cellular Spacing Selection of Cu-Mn Alloy under Ultrahigh Temperature Gradient and rapid solidification Condition

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2001年第1期17卷 84-86页

作者： Sen YANG Yunpeng SU Zhenxia LIU Weidong HUANG and Yaohe ZHOU State Key Laboratory of solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China Northwestern Polytech Univ State Key Lab Solidificat Proc Xian 710072 Peoples R China

Cellular spacing selection of Cu-27.3 wt pct Mn alloy has been investigated by laser surface rapid resolidification experiments. The experimental results show that there exists a wide distribution range in cellular spacing under ultra-high temperature gradient and rapid solidification conditions and the average spacing decrease with increase of the growth rate. The experimental results are compared with the current KGT model for rapid cellular/dendritic growth, and a reasonable agreement is found.

关键词： rapid solidification Ultrahigh Temperature Gradient cellular spacing temperature gradient rapid solidification selection of growth rate