共查询到20条相似文献,搜索用时 187 毫秒
1.
HREMSTUDYOFGRAINBOUNDARYPHASESINFe-Ni-Co-Nb-TiSUPERALLOYR.M.Wang;C.Z.Li;S.W.ZhangandM.G.Yan(1)InstituteofAeronauticalMaterial... 相似文献
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INVESTIGATIONONTHIN-WALLEFFECTOFADIRECTIONALLYSOLIDIFIEDSUPERALLOYBYUSINGTUBULARSPECIMENSR.Z.ChenandH.W.Zhang(BeijingInstitut... 相似文献
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STRAIN INDUCED STRUCTURAL TRANSITION OF INTERFACES AND TWINS IN A HOT-DEFORMED DUAL-PHASE TIAL ALLOY
STRAININDUCEDSTRUCTURALTRANSITIONOFINTERFACESANDTWINSINAHOT-DEFORMEDDUAL-PHASETIALALLOYCHENGuoFiang;WANGJinguo;ZHANGLichunand... 相似文献
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NEW METHODS FOR CALCULATING ACTIVITIES OF COMPONENTS FROM PHASE DIAGRAMS IN BINARY PERITECTIC SYSTEMS 总被引:3,自引:0,他引:3
Zhang Yongjun Hunan Superior Tech Materials Company Ltd. Changsha Zhang Xunying The Fourth Smelter Shuikoushan Mineral Bureau Henyang Fu Chongyue Department of Nonferrous Metallurgy Central South University of Technology Chang 《中国有色金属学会会刊》1997,(2)
NEWMETHODSFORCALCULATINGACTIVITIESOFCOMPONENTSFROMPHASEDIAGRAMSINBINARYPERITECTICSYSTEMS①ZhangYongjunHunanSuperiorTechMateri... 相似文献
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DEFORMATIONANDFRACTUREOFTiAlPSTCRYSTALSUNDERMONOTONICANDCYCLICLOADINGY.Umakoshi;T.NakanoandH.Y.Yasuda(DepartmentofMaterialsSc... 相似文献
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ADVANCEDHIGHGRADIENTTECHNOLOGYFORCASTINGOFSUPERALLOYTURBINEBLADESE.N.Kablov(All-RussianScientificResearchInstituteofAviationM... 相似文献
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Wang Qudong Jin Junze Research Center of Foundry Engineering Dalian University of Technology Dalian 《中国有色金属学会会刊》1997,(1)
INSITUGRADIENTDOUBLELAYERCOMPOSITESOFAlFeALLOYBYCENTRIFUGALCASTING①WangQudong,JinJunzeResearchCenterofFoundryEnginering,Dal... 相似文献
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EFFECTOFMICROSTRUCTUREONFATIGUECRACKINITIATIONOFSHOTPEENEDCOPPERANDBRASSK.W.Xu;N.S.HuandJ.W.He(State-KeyLaboratoryforMechanic... 相似文献
10.
XING Jinhai 《金属学报(英文版)》1996,9(2):103-108
BINDINGENERGYOFTHESHALLOWDONORIN(CdTe)_m/(ZnTe)_nSTRAINEDDOUBLEQUANTUMWELL¥XINGJinhai(DepartmentofPhysics,LiaoningUniversity,S... 相似文献
11.
为研究细晶AZ31镁合金薄板超塑气胀成形的最佳工艺参数,利用有限元软件对超塑胀形过程进行了有限元数值模拟分析。通过选取不同的应变速率敏感性指数和成形压力,来分析应变速率敏感性指数和成形压力对厚度分布均匀性的影响,同时对成形过程中的应变速率变化进行了模拟分析。模拟结果表明.应变速率敏感性指数和成形压力对厚度分布均匀性影响很大;应变速率分布情况良好,在所要求的应变速率范围之内,说明应变速率敏感性指数,压力等参数的设计合理。 相似文献
12.
Computational process models using membrane element method are developed in this paper for the superplastic forming of plane
strain boxes with complex cross-sectional details. Many practical superplastic components manufactured in industry have sloping
sidewalk with die bottoms either corrugated and/or at angles to the sides. The new method is used to develop process models
for such configurations and the resulting software can be used interactively in a computer. The method is useful to a designer
in the parametric study of die geometry, die wall friction, initial thickness, and material property, or to determine if a
specific geometry is suitable for superplastic forming. The kinematics of deformation are illustrated, and the numerical results
of the model are compared with continuum finite element solutions and also with experimental data. 相似文献
13.
Superplastic alloys and metals possess the ability to undergo large uniform strains prior to failure. Isothermal superplasticity of sheet metal is a phenomenon due to both peculiar process condition and material intrinsic characteristics. The material must have a grain size of less than 10 μm, the forming temperature of around half the absolute melting point and a very low strain rate (in the order of 10−5–10−3 s−1).The instability of superplastic flow under uniaxial stress state has been the subject of different studies. In this paper, under biaxial stress conditions, instability analysis of superplastic PbSn60 alloy using the finite element method is investigated. An original model has been implemented successfully in commercial finite element code in order to predict the imminent failure of material during superplastic forming processes. 相似文献
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The strain path and forming limit analysis of the lubricated sheet metal forming process 总被引:1,自引:1,他引:1
Few previous attempts have been made to analyze numerically the strain path and the forming limit in complex lubricated sheet metal forming. Since usual approaches of solving the lubrication model are limited to axisymmetric and plane strain cases only, this paper developed a unified procedure for combining the finite element code of sheet metal forming, the current lubrication/friction model and forming limit theory, to predict the strain path and fracture strains for either a steady or an unsteady three-dimensional process including both axisymmetric and plane strain cases. The availability of the method must be proved by a published problem, and an axisymmetric stretch forming process was therefore adopted as a benchmark. Numerical results showed that the present analysis provides good agreement with the experimental data of the strain path and the fracture strain for various tribological parameters such as lubricant viscosity and composite roughness of tooling and workpiece, and the advantage of the developed model is that it can be applied to solve the complicated 3D geometric problems. 相似文献
16.
Finite element modeling and optimization of superplastic forming using variable strain rate approach
Mohammad A. Nazzal Marwan K. Khraisheh Basil M. Darras 《Journal of Materials Engineering and Performance》2004,13(6):691-699
Detailed finite element simulations were carried out to model and optimize the superplastic blow forming process using a microstructure-based
constitutive model and a multiscale deformation stability criterion that accounts for both geometrical instabilities and microstructural
features. Optimum strain rate forming paths were derived from the multiscale stability analysis and used to develop a variable
strain rate forming control scheme. It is shown that the proposed optimization approach captures the characteristics of deformation
and failure during superplastic forming and is capable of significantly reducing the forming time without compromising the
uniformity of deformation. In addition, the effects of grain evolution and cavitation on the superplastic forming process
were investigated, and the results clearly highlight the importance of accounting for these features to prevent premature
failure.
This paper was presented at the International Symposium on Superplasticity and Superplastic Forming sponsored by the Manufacturing
Critical Sector at the ASM International AeroMat 2004 Conference and Exposition, June 8–9, 2004, in Seattle, WA. The symposium
was organized by Daniel G. Sanders, The Boeing Company. 相似文献
17.
壁厚分布对薄壁构件的结构性能有重要影响。本文研究超塑成形件壁厚分布的预测技术,实现了超塑成形过程的有限元数值模拟的成形件厚度分布曲线的自动预测,以半球壳和矩形盒成形为例,为自由胀形和约束胀表两种情形形件厚度变化进行了分析,预测结果与实验数据吻合。 相似文献
18.
G. Giuliano S. Franchitti 《International Journal of Machine Tools and Manufacture》2007,47(3-4):471-476
In recent years, there has been a considerable interest in the application of superplastic forming in the aircraft and automotive industries to realize complex parts. This requires a detailed design of the technological process in order to better exploit its peculiar potentialities. Nowadays, the finite element method represents the mainly used technique to plan the sheet metal forming processes whose simulation requires determination of material constants for superplastic materials. The aim of the present work is aimed to show a simple method to characterize superplastic materials. In this study, constant pressure free bulging for superplastic materials is analysed by finite element method and expressions to determine the constants of the superplastic materials have been proposed. In order to support the proposed method, numerical and experimental activities have been carried out which show the good reliability of values obtained from proposed expressions. 相似文献
19.
Y. -M. Hwang H. S. Lay J. C. Huang 《International Journal of Machine Tools and Manufacture》2002,42(12)
The purpose of this paper is to explore the plastic deformation behavior of the sheet during blow-forming of a superplastic sheet into an ellip-cylindrical closed-die by the finite element method. A finite element commercial code “DEFORM” is used to carry out the simulations and calculate the pressurization profile and sheet thickness distribution during the blow-forming process. A pressure control algorithm is proposed to keep the maximum strain rate in the deformation zone of the sheet equal to the target value, which corresponds to the highest m value of the material being superplastically formed. The effects of various forming conditions, such as the friction coefficient between the sheet and die and the aspect ratio of the die, on the forming pressure and thickness distribution of the product are discussed. Experiments using 8090 Al–Li sheets on superplastic blow-forming in an ellip-cylindrical closed-die are also carried out. The theoretical predictions of thickness distribution of the product are compared with experimental results. 相似文献
20.
以V型件弯曲和回弹过程为分析研究对象,通过对V型件弯曲及回弹过程的有限元数值模拟,分析获得了成形参数对V型件弯曲回弹的影响规律。结果表明:回弹角随弯曲角及材料的硬化系数的增大而增大,随材料的变形程度及硬化指数的增大而减小。 相似文献