简介:PrecipitationstudywascarriedoutinNi-35at.pctCralloybymeasuringelectricalresistivityatdifferentageingtemperaturesandlongageingtimes.Duringageing,itwasobservedthatelectricalresistivityinitiallyrosewithageingtimeandthenfellafterverylongageingataconstanttemperature.TheinitialincreaseinresistivityduringageingmaybeattributedtotheformationofGPzones/Cr-richprecipitatesatearlystagesbynucleationprocessanddecreaseinresistivity,andafterattainingamaximum,isduetothegrowthofprecipitateparticlesandsubsequentlybycoarseningoftheseprecipitates.TheresultsofelectricalresistivitymeasurementsduringageingwereconfirmedbyX-raydiffractionanalysisindicatingtheformationofaCr-richphaseandaCr3Ni2phaseintheNimatrix.
简介:AnumericalmodelAlloy/MhasbeenappliedtoinvestigatethemicrosegregationinAl-4.45wtpctCualloy.Thecalculateddatawerecomparedwiththeexperimentalmeasurementsforsamplessolidifiedatdifferentcoolingrates.Discrepanciesinsoluteconcentrationoccurbetweentheexperimentalobservationsandcalculatedresults.Reasonsforthediscrepancieswerediscussed,andtheeffectofdendritejoiningatalaterstageofsolidificationonthemicrosegregationwasinvestigated.Calculationsthathaveincludedthiseffectshowedabetterfitwithexperimentalresults.