简介:ThestoredenergyandtheenergyreleaseduringSPD(superplasticdeformation)ofaZn-5Alalloywerestudied.Thealloyafterrollingprocessgainsmorestoredenergy,andtheas-rolledspecimencanobtainmaximumelongationandminimumflowstresswithouthotholdingtreatmentbeforeSPD.ExperimentalresultsshowthatstoredenergyreleaseprocessisalongwithSPDprocessandisalsoanimpetustoSPD.Theas-rolledZn-5Alalloyhas48J/molstoredenergywhichwasmeasuredwithDSC(differentialscanningcalorimeter)andconformswelltothecalculatedvalue.Theas-rolledZn-5AlalloyafterSPDwithanelongationof2500%releases112J/molstoredenergy.Analysisshowsthatthestrainrateisindirectratiototherateofstoredenergyrelease.
简介:本文从观测常规产品Ni70Mn25Co5触媒合金片的表面缺陷入手,讨论了触媒片表观质量对金刚石合成效果的影响,从而也为触媒产品质量标准的制定提供了某些参考依据。
简介:X-raydiffraction(XRD)anddifferentialscanningcalorimetry(DSC)wereusedtoinvestigatethecrystallizationprocessofamorphousAl90TMxCe10-x(atomfractionin%;TM=FeorNi;x=3,5)alloys.AgingeffectswereexaminedbyX-raydiffraction.ThestructurecorrespondingtotheprepeakfortheamorphousAl90Fe5Ce5alloyismorestablethantheamorphousmatrix,butitisnotstableforamorphousAl90Ni5Ce5alloyduringthefirstcrystallizationstageandevendecomposesatroomtemperature.AlthoughbothAl-NiandAl-Fehavestrongchemicalbonding,thecrystallizationonsettemperatureofamorphousAl-Fe-CealloysismuchhigherthanthatofamorphousAl-Ni-Cealloys,whichislikelycausedbythedifferentstabilityofthestructurecorrespondingtotheprepeak.ThecrystallizationonsettemperatureincreasesasCe/NiratioincreasesinamorphousAl90NixCe10-xalloys,whereasitdecreasesasCe/FeratioincreasesinamorphousAl90FexCe10-xalloys.AbetteratomicpackingproducesasCecontentincreasesbecauseofthesizemismatchinAlNi-CesystemsandasFecontentincreasesbecauseoftheincreasingFecentralstructuralunits.