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

(整期优先)网络出版时间:1993-04-14
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Theeffectsofconcurrentpulsesinholdingdurationonsuperplasticityof2091Al-Lialloyhavebeeninvestigatedinthispaper.Theresultsofsuperplasticdeformationshowedthatconcurrentpulsesinholdingdurationdecreasedtheoptimumholdingtimeforsuperplasticdeformation(ε=3.33×10-2s,T=500℃)from15to5minandincreasedelongation(δ)from530to550%.Themetallographicobservationsshowedthatthespecimensappliedlybyconcurrentpulsewerecom-pletelyrecrystallizedafterholding5minat500℃,andgrainsrefinedtoabout2μm,andthosespec-imensunappliedcurrentpulseswerepartlyrecrystallizedevenafterholding15minat500℃.theelectronprobeanalysesindicatedthatconcurrentpulsespromotedatomicdiffusion.Itispointedoutthatconcurrentpulsesaccelerateatomdiffusionanddislocationmotion.increasenucleationrateofrecrystallizationanddecreasetheoptimumholdingtimeforsuperplasticdeformationandincreasesuperplasticproperties.