简介:DensityofmoltenNiandNi-Walloyswasmeasuredinthetemperaturerangeof1773~1873Kwithasessiledropmethod.ThedensityofmoltenNiandNi-Walloystrendstodecreasewithincreasingtemperature.ThedensityandmolarvolumeofthealloystrendtoincreasewithincreasingWconcentrationinthealloys.ThecalculationresultshowsanidealmixingofNi-Walloys.
简介:ThecreepbehaviorofAI2O3.SiO2fiberreinforcedZL109compositeshasbeeninvestigatedatfourtemperaturesrangingfrom553to623K.Theresultsshowhighstressexponentandhighapparentcreepactivationenergy.Agoodcorrelationbetweenthenormalizedcreeprateandnormalizedeffectivestressmeansthatthetruestressexponentofminimumcreepstrainrateofthecompositeisverycloseto5,andtheminimumcreepstrainrateismatrixlatticediffusioncontrolled.Thethresholdstressdecreaseswithincreasingtemperaturelinearlyanddisappearsatatemperaturecloseto623K.Itisassumedthatthelongrangeinternalbackstressesgeneratedincreepreducetheloadtransfertofibersandtheinteractionbetweendislocationsandstrengtheningprecipitatesdecreasesathightemperature.Atahightemperaturewherethelongrangeinternalbackstressesisveryclosetotheappliedstress,thethresholdstressdisappears.