Abstract
The refinementofcoarsegrainsincasturaniumcanleadtowrought-likeproperties.Inthisstudy,a bquenchedprocessiscoupledwithashock-loadingtechniqueand a-annealingtomanipulateuranium’s
grain sizeandtheresultingmicrostructureshavebeencharacterized.Neutronpowderdiffractionhas
been usedtoevaluatetheresidualstrainaccumulatedfromthethermo-mechanicaltreatments.Optical
microscopyandelectronbackscattering(EBSD)inscanningelectronmicroscopyhavebeenemployed
to evaluatethegrainsizevariationandthenatureofdeformationmechanisms,respectively.Large
strain anisotropyatthelatticelevelwasobservedonshock-loadedspecimens.Thefinalstressrelief
annealingdidnoteliminatealltheresidualstrain.Slipandtwinningwereobservedopticallyonthe
shockedspecimenswhileEBSDindicatesthatalthough{130},{172},and{112}deformationtwinswere
identified,anunusualtypeoftwinning‘{176}’/o5124 was foundtobedominant.Itisbelievedthat
the magnitudeofenergyappliedfavoredtheoccurrenceofthe{176}twininthepolycrystalline
uranium.Averagegrainsizeofcasturaniumunderwentasignificantreductionto 92 mm attheendof
the process.Theoverallresultsindicatetheshock-loadingapproachasapromisingsteptoward
controllingcasturaniumgrainsizeandthusitsmechanicalproperties.
