检索结果-南通市图书馆

Particle size dependence of the Microsegregation and microstructure in the atomized Ni-based superalloy powders:Theoretical and experimental study

引用

Journal of Materials Science & Technology 2024年第4期171卷 54-65页

作者： Jikang Li Mingsheng Yang Yunfei Cai Yuanyuan Zhang Qingshuai Feng Jiantao Liu Tong Liu Key Laboratory of Aerospace Materials and Performance(Ministry of Education)School of Materials Science and Engineering Beihang UniversityBeijing 100191China Central Iron and Steel Research Institute Beijing 100081China

The microstructure and Microsegregation of atomized powder,which depend on their sizes,are of great importance to the mechanical properties of the consolidated bulk materials.Therefore,it is necessary to reveal the relationship between particle size and powder attributes.The effects of particle size on the so-lidification characterization of the atomized Ni-based superalloy powders were studied via finite element simulation.Based on the simulations,a model was developed to predict the Microsegregation and mi-crostructure of atomized powders with different sizes and study the influence of thermal history on the powder attributes during the atomization processes.The radiation heat transfer and temperature gradi-ent within the rapid solidification alloy powders were taken into account in this model.For validating the accuracy of the model,the predictions of the present model were compared with the Microsegregation and microstructure of the specific size powder close to the screen mesh size.The results showed that mi-crostructure depended primarily on the temperature gradient within the powder,while the solidification rate had a more significant effect on the Microsegregation.The model predicted microstructure features in agreement with the experiment,and for Microsegregation,the deviations of prediction for most ele-ments were less than 10%.This work provides a new model to precisely predict the Microsegregation and microstructure of the atomized alloy powders and sets a foundation to control the powder features for various engineering applications.

关键词： Particle size Solidification microstructure Microsegregation Numerical simulation

来源：

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

On Ti6Al4V Microsegregation in Electron Beam Additive Manufacturing with Multiphase-Field Simulation Coupled with Thermodynamic Data

引用

Acta Metallurgica Sinica(English Letters) 2022年第3期35卷 425-438页

作者： Yujian Wang Shuo Chu Zhijun Wang Junjie Li Jincheng Wang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China

Electron beam additive manufacturing is an effective method for the fabrication of complex metallic components.With rapid solidification,the characteristics of Microsegregation within the interdendritic region are interesting and important for the subsequent phase transformation and final mechanical properties.However,in view of the microsecond lifetime and the small length scale of the molten pool,experimentally investigating Microsegregation is challenging,even with electron probe micro-analysis.In this study,a multiphase-field model coupled with the real thermodynamic data of Ti6Al4V alloy was successfully developed and applied to simulate the rapid solidification of columnarβgrains via electron beam additive manufacturing.The thermal gradient(G)and cooling rate(R)were obtained from a 3D powder-scale multiphysics simulation and provided as inputs to a multiphase-field model.The eff ects of the electron beam process parameters and thermal conditions on the columnarβgrains were investigated.Liquid films and droplets were observed to have solute enrichment in the intercellular region.The size of the liquid film increased at a lower scanning speed and energy power.Increasing the scanning speed and energy power refined the columnarβgrains and decreased the liquid film size.The extent of Microsegregation considerably increased at lower energy power,whereas the change in scanning speed had little eff ect on the Microsegregation.The results also indicate that solute vanadium results in significant solute trapping and Microsegregation during the rapid solidification of the Ti6Al4V alloy.

关键词： Ti6Al4V alloy Microsegregation Electron beam additive manufacturing Multiphase-field model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of nitrogen on microstructure and Microsegregation of martensitic stainless steel 4Cr13 produced by electroslag remelting

引用

Journal of Iron and Steel Research(International) 2023年第9期30卷 1854-1861页

作者： Shou-hui Li Jing Li Jie Zhang Cheng-bin Shi State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

Two ingots of 4Cr13 martensitic stainless steel with different nitrogen contents,0.023 and 0.121 mass%,were produced by vacuum induction furnace and electroslag remelting.The microstructure and the Microsegregation of the electroslag remelting ingot were analyzed by optical microscopy,scanning electron microscopy and electron microprobe analysis.Thermo-Calc software was used to calculate the nitrogen solubility changes during solidification of high nitrogen martensitic stainless steel and the equilibrium and non-equilibrium phase diagrams of 4Cr13 steel with different nitrogen contents.The solubility of nitrogen in 4Cr13 steel reached the lowest value of 0.118%before the start of the peritectic reaction.The microstructure of 4Cr13 steel was martensite,retained austenite and primary carbide M_(7)C_(3).Higher nitrogen content increased the content of retained austenite in martensitic stainless steel,inhibited the precipitation of primary carbides and refined the dendrites.Higher nitrogen content could effectively inhibit the Microsegregation of C element in martensitic stainless steel;however,it had little effect on Cr,V,Nb and Ti.The peritectic reaction was first carried out in high nitrogen steel during solidification,which advanced the transformation of austenite and inhibited the Microsegregation of C element.

关键词： Nitrogen Martensitic stainless steel Electroslag remelting Microsegregation Microstructure

来源：

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

Quantitative effects of phase transition on solute partition coefficient,inclusion precipitation, and Microsegregation for high-sulfur steel solidification

引用

Journal of Materials Science & Technology 2019年第10期35卷 2383-2395页

作者： Lintao Gui Mujun Long Shixin Wu Zhihua Dong Dengfu Chen Yunwei Huang Huamei Duan Levente Vitos State Key Laboratory of Coal Mine Disaster Dynamics and Control College of Materials Science and EngineeringChongqing UniversityChongqing400044China Department of Materials Science and Engineering KTH Royal Institute of TechnologyStockholm10044Sweden Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing400044China

Segregation and inclusion precipitation are the common behaviours of steel solidification, which are resulted from the redistribution and diffusion of the solute elements at the solid-liquid interface. The effect of the phase transition of high-sulfur free-cutting steel is quantified in the present work for the solute partition coefficient(ki), inclusion precipitation, and Microsegregation by establishing a coupling model of Microsegregation and inclusion precipitation, wherein the quantified dependencies of ki in terms of temperature, phase and carbon(C) content were applied. Results showed that the solidification temperature range and phase transition of high-sulfur steel that under different solidification paths and C contents were quite different, leading to differences in ki and eventually in Microsegregation. kC,kP, and kS were mainly affected by phase composition and kSi was primarily by temperature, while kMn depended on both phase composition and temperature during solidification. Increasing the C content within the interval 0.07-0.48 wt%, the ‘proportion of the δ phase maintained temperature region during solidification’(Pδ), kave Pand kave S(kiave, the average value of the ki across the whole stages of solidification)decreased monotonically, whereas kave Cincreased linearly. The peritectic reaction impacted on the phase composition and ki, leading to the change in Microsegregation. Such effect of the peritectic reaction was more significant at the last stage of solidification. When the Pδ was between 75% and 100%(corresponding to 0.07-0.16 wt% C), the solidification path resulted in a greater effect on the Microsegregation of solutes C, P, and S because of the peritectic reaction. The Microsegregation of solutes Mn and S were comprehensively influenced by kMn, kS and Mn S precipitation as well. The studies would help reveal the solute redistribution at the solid-liquid interface, and improve the segregation of high-sulfur steel by controlling the solidification and precipitation in practice.

关键词： Phase transition Microsegregation Solute partition coefficient Inclusion precipitation High-sulfur steel

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Revisiting dynamics and models of Microsegregation during polycrystalline solidification of binary alloy

引用

Journal of Materials Science & Technology 2021年第15期74卷 155-167页

作者： Tongzhao Gong Yun Chen Shanshan Li Yanfei Cao Dianzhong Li Xing-Qiu Chen Guillaume Reinhart Henri Nguyen-Thi Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei230026China Aix Marseille Univ Universite de ToulonCNRSIM2NPMarseilleFrance

Microsegregation formed during solidification is of great importance to material properties.The conventional Lever rule and Scheil equation are widely used to predict solute segregation.However,these models always fail to predict the exact solute concentration at a high solid fraction because of theoretical assumptions.Here,the dynamics of Microsegregation during polycrystalline solidification of refined Al-Cu alloy is studied via two-and three-dimensional quantitative phase-field simulations.Simulations with different grain refinement level,cooling rate,and solid diffusion coefficient demonstrate that solute segregation at the end of solidification(i.***.when the solid fraction is close to unit)is not strongly correlated to the grain morphology and back diffusion.These independences are in accordance with the Scheil equation which only relates to the solid fraction,but the model predicts a much higher liquid concentration than simulations.Accordingly,based on the quantitative phase-field simulations,a new analytical Microsegregation model is derived.Unlike the Scheil equation or the Lever rule that respectively overestimates or underestimates the liquid concentration,the present model predicts the liquid concentration in a pretty good agreement with phase-field simulations,particularly at the late solidification stage.

关键词： Microsegregation Grain refinement Cooling rate Back diffusion Phase-field method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of titanium and rare earth microalloying on Microsegregation,eutectic carbides of M2 high speed steel during ESR process

引用

Journal of Rare Earths 2020年第9期38卷 1030-1038,I0005页

作者： Fuxing Yin Lu Wang Zhixia Xiao Jianhang Feng Lin Zhao School of Materials Science and Engineering Hebei University of TechnologyTianjin 300130China Research Institute for Energy Equipment Materials Hebei University of TechnologyTianjin 300130China Tianjin Key Laboratory of Materials Laminating Fabrication and Interfacial Controlling Technology Tianjin 300130China Central Iron and Steel Research Institute Beijing 100081China

The effects of RE and Ti microalloying during electroslag remelting(ESR)process on the Microsegregation and morphology of eutectic M2C carbides in M2 high speed steel were investigated.The results show that the addition of 0.2 wt%RE can alleviate the segregation of C,W,Mo,V and Cr,while the morphology of eutectic M2C carbides hardly changes.The microalloying with the addition of 0.5 wt%Ti has the lowest degree of Microsegregation due to the improvement of primary dendrites by the effective heterogeneous nucleating agent of(Ti,V)(C,N)particles.The addition of Ti makes the mo rphology of M2C carbides change from rod-like or maze-like shape into a coarse feathery shape,exhibiting anisotropic facet growth characteristics.For the microalloying of 0.2 wt%RE and 0.5 wt%Ti,the segregation of the main metal alloying elements is slightly more severe than that of the addition of only RE or Ti.Under the combined action of RE and Ti,the feathery eutectic M2C becomes thinner and shorter and tends to be isolated or distributed in a discontinuous network.

关键词： Microsegregation Morphology Eutectic carbides High speed steel Electroslag remelting Rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of cooling rate on microstructure,Microsegregation and mechanical properties of cast Ni-based superalloy K417G

引用

Journal of Materials Science & Technology 2018年第5期34卷 811-820页

作者： Li Gong Bo Chen Long Zhang Yingche Ma Kui Liu Institute of Metal Research Chinese Academy of Sciences

The effects of different solidification rates after pouring on the microstructures,Microsegregation and mechanical properties of cast superalloy K417 G were investigated.Scheil-model was applied to calculate the temperature range of solidification.The casting mould with different casting runners was designed to obtain three different cooling rates.The microstructures were observed and the Microsegregation was investigated.Also,high temperature tensile test was performed at 900℃ and stress rupture test was performed at 950℃ with the stress of 235 MPa.The results showed that the secondary dendrite arm spacing,Microsegregation,the size and volume fraction of γ＇phase and the size of γ/γ＇eutectic increased with decreasing cooling rate,but the volume fraction of γ/γ＇ eutectic decreased.In the cooling rate range of 1.42℃s^-1–0.849 s^-1,the cast micro-porosities and carbides varied little,while the volume fraction and size of phase and γ/γ＇ eutectic played a decisive role on mechanical properties.The specimen with the slowest cooling rate of 0.84℃ s^-1 showed the best comprehensive mechanical properties.

关键词： Ni-based cast superalloy Cooling rate Microstructure Microsegregation Mechanical property

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Microstructure and Microsegregation of directionally solidified Ti–45Al–8Nb alloy with different solidification rates

引用

Rare Metals 2016年第1期35卷 70-76页

作者： Xiang-Jun Xu Lin Song Xiao-Ou Jin Dong-Dong Han Xin Wang Jun-Pin Lin Materials and Chemistry School Zhongyuan University of Technology State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing School of Architecture and Engineering Heilongjiang University

Microstructure and Microsegregation of directionally solidified Ti-45Al-8Nb alloy were investigated by scanning electron microscopy（SEM）,transmission electron microscopy（TEM） and electron probe microanalyzer（EPMA）.For the alloy solidified at the solidification rates（v） ranging from 10 to 400 μm·s^（-1）,the microstructure of the mushy zone exhibits a cellular-dendritic structure at lower growth rate（v=10-50 μm·s^（-1）） and a typical dendritic morphology at higher growth rate（v = 100-400 μm·s^（-1））.The relationship between primary dendrite arm spacing（λ_1）and v is λ_1=1.08×10~3v^（-0.35）.Al and Nb elements segregate at interdendritic zone and in the dendritic core,respectively.In solid of mushy zone,a relatively flat concentration profile is observed for the typical dendrite structure,and Nb enriches in B2 phase induced by β→α＋βtransformation.The content of B2 phase is hardly affected by v.The extent of Microsegregation in steady-state zone decreases at a lower growth rate because holding the samples at higher temperature after solidification for a long time can homogenize the solid effectively.

关键词： Nb-containing TiAl alloy Solidification Microstructure Microsegregation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of partition coefficient on Microsegregation during solidification of aluminium alloys

引用

International Journal of Minerals,Metallurgy and Materials 2014年第10期21卷 980-989页

作者： M.H.Avazkonandeh-Gharavol M.Haddad-Sabzevar H.Fredriksson Department of Metallurgy and Materials Engineering Faculty of Engineering Ferdowsi University of Mashhad Department of Materials Science and Engineering School of Industrial Engineering and Management Royal Institute of Technology

In the modeling of Microsegregation, the partition coefficient is usually calculated using data from the equilibrium phase diagrams. The aim of this study was to experimentally and theoretically analyze the partition coefficient in binary aluminum--copper alloys. The sam- ples were analyzed by differential thermal analysis （DTA）, which were melted and quenched from different temperatures during solidifica- tion. The mass fraction and composition of phases were measured by image processing and scanning electron microscopy （SEM） equipped with an energy-dispersive X-ray spectroscopy （EDS） unit. These data were used to calculate as the experimental partition coefficients with four different methods. The experimental and equilibrium partition coefficients were used to model the concentration profile in the primary phase. The modeling results show that the profiles calculated by the experimental partition coefficients are more consistent with the experi- mental profiles, compared to those calculated using the equilibrium partition coefficients.

关键词： aluminum copper alloys solidification partition coefficient Microsegregation numerical modeling differential thermal analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Simulation of the Dendrite Morphology and Microsegregation in Solidification of Al–Cu–Mg Aluminum Alloys

引用

Acta Metallurgica Sinica(English Letters) 2015年第2期28卷 173-181页

作者： Rui Chen Qing-Yan Xu Bai-Cheng Liu Key Laboratory for Advanced Materials Processing Technology Ministry of Education School of Materials Science and Engineering Tsinghua University

Since most typical alloys in industrial applications are multicomponent with three or more components, and various CA models proposed in the past mainly focus on the binary alloys, a two-dimensional modified cellular automaton model allowing for the quantitatively predicting dendrite growth of multicomponent alloys in the low P6clet number regime is presented. The elimination of the mesh-induced anisotropy is achieved by adopting a modified virtual front tracking method. A new efficient method based on the lever rule is applied to calculate the solid fraction increment of the interfacial cells. The thermodynamic data such as liquidus temperature, the partition coefficients, and the slope of liquidus surface, needed for determining the dynamics of dendrite growth, are obtained by coupling with PanEngine. This model is applied to simulate the dendrite morphology and Microsegregation of A1-Cu-Mg temary alloy both for single and multi- dendrites growth. The simulated results demonstrate that the difference of the concentration distribution profiles ahead of the dendrite tip for each alloying element mainly results from the different partition coefficients and solute diffusion coefficients. Comparison with the prediction of analytical model is carded out and it reveals the correctness of the model. Consequently, the difference in interdendritic Microsegregation behavior of different components is analyzed.

关键词： Cellular automaton Multicomponent Dendrite growth Microsegregation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：