Effect of AIN Particulate Size on Superplasticity of AINp/6061 Al Composites

In recede years, superplasticity has been demonstrated in many discontinuously reinforcedcomposites [l--16]. These stUdies proved thatsuperplasticity is observed at very high strainrate (10--z--10 s--'). Although high strain ratesuperplasticity has been observed in variousaltuninum alloy composites, it has not been understood how particulate size of reinforcementhas an effect on HSRS behavior of Al-Manixcomposites. It is necessary, therefore, to investigate superplastic characteristics of A…     

THE INFLUENCE OF CAVITY DAMAGE ON MECHANICAL PROPERTIES OF SUPERPLASTICALLY-DEFORMED MATERIALS AND ITS PREDICTION

1.IhtroductionSuperplasticmaterials,whichexhibitextraoulinalllylargeelongationandlowflowstress,havebeenfoundtobeofgreatvalueinindustrialapplications,especiallyintheaerospaceindusal.Unfortunately,Inanysuchmaterialsarepronetocavitationduringsuperplashcdefonnation,whichdelightsthefoeingabilitiesanddecreasesthemechAncalpropertiesataamtemperaturepeatly,sothemechanicalpropertiesofsuperplastically--deformedpatshavereceivedconsideboleattentionduringthepastfewyears.InvestigationswerePerformedon7475alt…     

APPLICATION OF GLEEBLE 1500 ON SUPERPLASTICITY

1.~nonSuperylasticityisakindofphenomenonthatdefonnationresistanceisreducedrelnalkablyandplasticity----especiallyelongation----isremarkablyincreased.Therehasbeenoaly30years'historyforsuperplasticityresearchintheworld.Anewsubjectandanewtechnologyofsuperplasticityincludingbranchesofmaterials,mechanism,mechhocs,forminghavebeenfoundedyet.Superplasticityisbasicallyanexperimentalsubject.Itstheoryandresultsareestablishedonthebaseofexperiments.Superplasticexperimentsmainlyincludetwokinds----mechwhcala…     

强烈塑性变形超塑材料研究进展

强烈塑性变形可以用于制备超细晶金属材料,超细晶金属材料一个典型的特性是具有高应变率和/或低温超塑性。介绍利用强烈塑性变形研制超塑铝、镁合金的研究近况,并对强烈塑性变形超塑材料的研究进行展望。     

工程陶瓷材料的制造、加工与超塑性

简要介绍工程陶瓷材料的制造与机械加工研究的进展 ,以及当前我国工程陶瓷材料超塑性研究的结果与动向     

Effect of Concurrent Pulse in Holding Duration on Superplasticity of 2091Al-Li Alloy

The effects of concurrent pulses in holding duration on superplasticity of 2091 Al-Li alloy have beeninvestigated in this paper.The results of superplastic deformation showed that concurrent pulses inholding duration decreased the optimum holding time for superplastic deformation(ε=3.33×10~(-2) s~,T=500℃)from 15 to 5 min and increased elongation(δ)from 530 to 550%.Themetallographic observations showed that the specimens appliedly by concurrent pulse were com-pletely recrystallized after holding 5 min at 500℃,and grains refined to about 2μm,and those spec-imens unapplied current pulses were partly recrystallized even after holding 15 min at 500℃.theelectron probe analyses indicated that concurrent pulses promoted atomic diffusion.It is pointed outthat concurrent pulses accelerate atom diffusion and dislocation motion.increase nucleation rate ofrecrystallization and decrease the optimum holding time for superplastic deformation and increasesuperplastic properties.     

H62黄铜超塑性压缩变形后的组织与性能

通过对Ｈ６２黄铜超塑性压缩变形后的试样进行金相组织分析和硬度试验，以选择最佳的超塑性压缩变形参数。     

超轻镁合金的研究历史与发展现状

首次系统介绍了超轻镁合金的研究历程。从合金化、复合材料、快速凝固与超塑性四个方面介绍了国内外的研究现状，展望了超轻镁合金的发展前景。     

超塑性变形的应力应变速率关系

文章详细分析了方程σ=kε~m的优缺点及适用范围,提出了超塑性的定义并引入了极限超塑性和有效应变速率敏感性指数的概念。在此基础上,讨论了流动应力不同部分—内应力及有效应力对超塑性变形的作用,据此导出一个超塑性流动应力与应变速率之间的关系式。该关系式能深入地说明有关的超塑性行为,理论结果与实验数据一致。     

40Cr钢的恒温超塑性焊接

探讨了利用情理温超塑性实现４０Ｃｒ钢固相焊接的可行性及影响因素，并对超塑焊接接头及组织进行了观察与分析，试验表明，经超细化处理后的４０Ｃｒ钢在超塑性变形温度及应变速率范围内经短时超塑压接即可实现接头力学性能与基体相同的固相焊接。