简介:ThehomogeneousplasticflowoffullyamorphousandpartiallycrystallizedZr41.2Ti13.8Cu12.5Ni10Be22.5bulkmetallicglass(Vitl)hasbeeninvestigatedbycompressiontestsathightemperaturesinsupercooledliquidregion.Experimentalresultsshowthatatsufficientlylowstrainrates,thesupercooledliquidofthefullyamorphousalloyrevealsNewtonianflowwithalinearrelationshipbetweentheflowstressandstrainrate.Asthestrainrateisincreased,atransitionfromlinearNewtoniantononlinearflowisdetected,whichcanbeexplainedbythetransitionstatetheory.Overtheentirestrainrateintervalinvestigated,however,onlynonlinearflowispresentinthepartiallycrystallizedalloy,andtheflowstressforeachstrainrateismuchhigher.Itisfoundthatthestrainrate-stressrelationshipforthepartiallycrystallizedalloyatthegiventemperatureof646Kalsoobeysthesinhlawderivedfromthetransitionstatetheory,similartothatoftheinitialhomogeneousamorphousalloy.Thus,itisproposedthattheflowbehaviorofthenanocrystalline/amorphouscompositeat646Kismainlycontrolledbytheviscousflowoftheremainingsupercooledliquid.