摘要
Theglidingbehaviorofedgedislocationnearagrainboundary(GB)incopperunderpureshearstressesissimulatedbyusingmoleculardynamics(MD)method.Many-bodypotentialincorporatingtheembeddedatommethod(EAM)isused.ThecriticalshearstressesforasingledisocationtopassacrossGBsurfaceareobtainedatvaluesofσ_c=23MPa～68MPaand137MPa～274MPafor∑=165smallangletiltGBat300Kand20K,respectively.Thefirstresultagreeswiththeexper-imentalyieldstressσ_y(=42MPa)quitewell.ItsuggeststhattheremightbeoneofthereasonsofinitialplasticyieldingcausedbysingledislocationglidingacrossGB.Inaddition,theremightbepossibilitytoobtainyieldstrengthfrommicroscopicanal-ysis.Moreover,theexperimentalvalueofσ_yatlowtemperatureisgenerallyhigherthanthatatroomtemperature.So,theseresultsareinconformityqualitativelywithexperimentalfact.Ontheotherhand,the∑=25GBistoostronganobstacletothedislocation.Inthiscase,adislocationisabletopassacrossGBunderrelativelylowstressonlywhenitisdrivenbyotherdislocations.Thisistakentomeanthatdislocationpile-upmustbebuiltupinfrontofthiskindofGB,ifthisGBmaytakeeffectontheprocessofplasticdeformation.
出版日期
1996年01月11日（中国期刊网平台首次上网日期，不代表论文的发表时间）
