检索结果-南通市图书馆

Transactions of Nonferrous Metals Society of China 2009年第S2期19卷 418-422页

作者：蒋少松张凯峰 National Key Laboratory for Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China

Firstly,the relation between the coefficient of thermal expansion(CTE)and the volume fraction of TiO_(2) was investigated, and also the influence of relative density of ceramic on the CTE was studied.The results show that the volume fraction of TiO_(2) and the relative density both make influence on the CTE of ZrO_(2)-TiO_(2) ceramic.According to the results,the ZrO_(2)-TiO_(2)(volume fraction of TiO_(2) is 27%)ceramic die with the similar CTE(8.92×10^(-6) ℃^(-1))to Ti6Al4V was fabricated.Secondly,to evaluate the dimensional accuracy of the workpiece superplastically formed,the Ti6Al4V impression experiment was performed.The result shows that the dimensional inaccuracy of workpiece is 0.003.Thirdly,in order to evaluate the practicability,the experiment of superplastic forming Ti6Al4V using ZrO_(2)-TiO_(2) cylinder ceramic die was carried out.The Ti6Al4V cylinder shows good shape retention and surface quality,and high dimensional accuracy.The ceramic dies seem to be adequate for superplastic forming the high accuracy Ti6Al4V, and the trials have confirmed the potential of the ZrO_(2)-TiO_(2) ceramic die.

关键词： Ti6Al4V superplastic forming ceramic die linear coefficient of thermal expansion

superplastic forming and Diffusion Bonding for Sandwich Structure of Ti-6Al-4V Alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2005年第1期21卷 60-62页

作者： Wenbo HAN, Kaifeng ZHANG, Guofeng WANG and Xiaojun ZHANGSchool of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, ChinaProf., Ph.D., Sch. of Mat. Sci. and Eng. Harbin Inst. of Technol. Harbin 150001 China

superplastic forming and diffusion bonding (SPF/DB) is a well-established process for the manufacture of components almost exclusively from Ti-6AI-4V sheet material. The sandwich structure of Ti-6AI-4V alloy is investigated. The effects of the microstructure on the SPF/DB process were discussed. The microstructure at the interfaces and the distribution of thickness were researched.

关键词： superplastic forming Diffusion bonding Sandwich structure TI-6A1-4V alloy

Deformation Behavior of Zr_(65)Cu_(17.5)Ni_(10)Al_(7.5)in superplastic forming with Silicon Mould: Simulation and Application

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2014年第2期29卷 250-255页

作者：杨璠 SHI Tielin YU Qiang 廖广兰 State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology

We investigated the deformation behaviors of Zr_65Cu_17.5Ni_10Al_7.5 in superplastic forming in silicon mould via numerical modeling and experiments. The data needed for the constitutive formulation were obtained from compressive tests to establish a material library for finite-element simulation using a DEFORM 3D software. A constant speed forming process of a micro gear was modeled where the loading force, feature size and amount of deformation in the micro gear in silicon mould were analyzed in detail for the optimal requirements of micro gear forming and the protection of silicon mould. Guided by the modeling parameters, an amorphous metal micro gear was successfully obtained by our home-made superplastic forming system with the optimized parameters （temperature of 683 K, top speed of 0.003 mm/s until the load force reaching limiting value at 1960 N, and a gradually decelerating process for holding the force to the end）. Our work gives a good example for optimization of superplastic forming and fabrication of BMGs in microparts.

关键词： bulk metallic glass deformation finite-element simulation superplastic forming silicon mould

MODELING　OF　superplastic　forming　PROCESS　FOR　ALUMINUM　ALLOYS　WITH　STRAIN　HARDENING　EFFECT

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1996年第6期9卷 537-544页

作者： Y.N. Kwon and Y.-W. Chang(Center for Advanced Aerospace Materials (CAAM), Pohang University of Science and Technology, Pohang 790-784. Korea ) Pohang Univ of Science and Technology Pohang South Korea

superplastic forming of a thin sheet into complex shape is an important manufacturing process especially in aerospace industry. The main objective of modeling the superplastic forming process is to predict the forming pressure-time cycle to maintain the optimum strain rate and the resulting thickness distribution. There have been many attempts to model superplastic forming process using the various techniques including finite element method. However, most of these attempts so far have disregarded the strain hardening effect which occurs in several superplastic materials. In this study,we have used ABAQUS finite element code to predict the suitable processing variables during an axisymmetric cup forming of Supral 100 and 7075Al alloys to examine the strain hardening effects on forming. The performance of numerical results was then compared with the experimental results.

关键词： superplastic forming strain hardening supral 100 7075Al FEM

Calculation of Structural Characteristics Evolution during superplastic forming of Shells by"SPLEN-O"Application Computer Program Set

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 111-112页

作者： E.Chumachenko M.Tsepin A.Tchekine O.Panina Dept.of Applied Mathematics of Moscow institute of Electronics&Mathematics MoscowRussia Dept.of Technology of Moscow State institute of Steels&Alloys(Technological University) MoscowRussia

The applications of commercial computer program set "SPLEN-O" based on finite elements method (FEM) for the simulation of superplastic forming (SPF) technology of shells are described. The changes in characteristics of ultrafine-grained (UFG) structure during deformation are taken into account in function of viscosity and solving algorithm. Some examples are shown to illustrate the possibilities of FEM simulation for prediction of numerical grain-size data on different SPF stages of shells.

关键词： Structural Characteristics finite elements method superplastic forming computer program FEM simulation

superplastic forming of Silicon Nitride at Low Temperature

在线全文

学校读者我要写书评

暂无评论

Superplastic Forming of Silicon Nitride at Low Temperature

Surface Modelling and Mesh Generation for Simulating superplastic forming

The 3～〔rd〕International Conference on High-Performance Ceramics(CICC-3)（2）

作者： Junting Luo.Kaifeng Zhang, Guofeng Wang and Guoqing Chen National Key Laboratory of Precision Hot Processing, Harbin Institute of Technology, Harbin 150001, China

SiN ceramic bodies were prepared by liquid phase sintering (LPS) with the amorphous nano-sized Si3N4 powders. Nano-sized A12O3 and Y2O3 powders were introduced as additives. XRD analysis showed that the sintered body consists of β-Si3N4 and Si2N2O which confirms that phase change temperature of β-Si3N4 is lower than traditional Si3N4. SEM examination showed that the grain size of sintered body is smaller than 300 nm. superplastic forming can be undertaken at the low temperature of 1550℃in a nitrogen atmosphere when the forming velocity is less than 0.5 mm/min. The formed parts rupture when the forming velocity is 1 mm/min or the forming temperature is 1500℃. Only a few defects are observed in the blank before forming, but many cavity groups are present in the formed workpiece.

关键词： Silicon nitride superplastic forming Cavity groups

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Computer Aided Drafting,Design and Manufacturing 2002年第2期12卷 10-18页

作者： ZhaoHongsheng LinJianguo CollegeofMechanicalEngineering TaiyuanUniversityofTechnologyTaiyuan030024China SchoolofManu andMechEngineeringUniversityofBirminghamBirminghamB15UK

This paper presents an approach which enables surface modelling, mesh generation and the Finite Element (FE) analysis to be integrated together to simulate superplastic forming process for complex shaped components. Techniques have been developed to generate an FE mesh over non-four-sided surface areas, the boundaries of which are Bezier curves of arbitrary degree, using a consistent expression. Theoretical evidence is given to determine the number of Bezier triangular patches required for accurately re-constructing die surfaces within a commercial FE solver. The developed techniques have been successfully used in determining the process parameters for forming a 3D rectangular box.

关键词： surface modelling mesh generation superplastic forming

PRE-DRAWING AND AIR-BULGING TECHNOLOGY OF superplastic forming FOR AUTOMOBILE MODELS

在线全文

学校读者我要写书评

暂无评论

PRE-DRAWING AND AIR-BULGING TECHNOLOGY OF SUPERPLASTIC FORMI...

superplastic Microforming of Zn-A122 Alloy Ribs

2006年中国机械工程学会年会暨中国工程院机械与运载工...

作者： CHEN Songmao, XUE Xin, PENG Yanhua, RUAN Feng School of Mechanical Engineering, South China University of Technology, Guang Zhou 510640, China

The forming of automobile models with big and complex surfaces is difficult in the practical work. The phenomena of cracking, time-consuming and non-uniform distribution of sheet thickness occurs in t

关键词： superplastic forming air-bulging finite element drawing automobile models.

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2004年第2期20卷 236-238页

作者： Changli WANG, and Kaifeng ZHANGSchool of Materials Science arid Engineering, Harbin Institute of Technology, Harbin 150001, China Sch. of Mat. Sci. and Eng. Harbin Inst. of Technol. Harbin 150001 China

Research on microforming of fine-grained superplastic Zn-AI22 alloy was carried out in this paper by means of superplastic forming. With the selected material, microformability tests have been carried out with the specially developed evaluation method by using two kinds of stainless steel dies. With these dies, micro-extrusion tests have been carried out and the characteristics of microformability of the material have been clarified. Effects of processing parameters and die structure on forming have been analyzed. SEM and metallographic microscope have been used to analyze the formed specimens. Through analysis of flow lines of the formed specimen, behavior of material could be understood well.

关键词： superplastic forming Microformability Rib

superplastic formability of Ti-6Al-4V butt-welded plate by laser beam welding

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2009年第S2期19卷 429-433页

作者：王刚张文丛张功磊徐志良 School of Materials Science and Engineering Harbin Institute of Technology at WeihaiWeihai 264209China

The superplasticity of Ti-6Al-4V butt-welded plates by laser beam welding(LBW)was studied in virtue of hot tensile tests and superplastic bulging tests.Furthermore,microstructural evolution of weld metal upon superplastic forming was systematically analyzed via metallographical tests and scanning electron microscope(SEM).The relation between the microstructure of weld metal and its superplastic ability was discussed.The experimental results show that Ti-6Al-4V butt-welded plates by LBW possess superplasticity.The maximum elongation is up to 154%and the maximum bulge height can be up to 1.81 times the internal radius of the female die.There is an optimum value of the bulge height for bulging gas pressure.

关键词： superplastic forming Ti-6Al-4V laser beam welding