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1、2021/2/71Ch2位錯2.1位錯理論的產(chǎn)生2.2位錯的幾何性質(zhì)2.3位錯的彈性性質(zhì)2.4位錯與晶體缺陷的相互作用2.5位錯的動力學性質(zhì)2.6實際晶體中的位錯2021/2/722.1位錯理論的產(chǎn)生一、晶體的塑性變形方式二、單晶體的塑性變形三、多晶體的塑性變形四、晶體的理論切變強度五、位錯理論的產(chǎn)生六、位錯的基本知識2021/2/732.2位錯的幾何性質(zhì)一、位錯的幾何模型二、柏格斯矢量三、位錯的運動四、位錯環(huán)及其運動五、位錯與晶體的塑性變形六、割階2021/2/742.3位錯的彈性性質(zhì)一、彈性連續(xù)介質(zhì)、應(yīng)力和應(yīng)變二、刃型位錯的應(yīng)力場三、螺型位錯的應(yīng)力場四、
2、位錯的應(yīng)變能五、位錯的受力六、向錯七、位錯的半點陣模型2021/2/752.4位錯與晶體缺陷的相互作用一、位錯間的相互作用力二、位錯與界面的交互作用三、位錯與點缺陷的交互作用2021/2/76InteractionsBetweenDislocationsWewillfirstinvestigatetheinteractionbetweentwostraightandparalleldislocationsofthesamekind.Ifwestartwithscrewdislocations,wehavetodistinguishthefollowingca
3、ses:2021/2/77Inanalogy,wenextmustconsidertheinteractionofedgedislocations,ofedgeandscrewdislocationsandfinallyofmixeddislocations.Thecaseofmixeddislocations-thegeneralcase-willagainbeobtainedbyconsideringtheinteractionofthescrew-andedgepartsseparatelyandthenaddingtheresults.Withthe
4、formulasforthestressandstrainfieldsofedgeandscrewdislocationsonecancalculatetheresolvedshearstresscausedbyonedislocationontheglideplaneoftheotheroneandgeteverythingfromthere.Butforjustobtainingsomebasicrules,wecandobetterthanthat.Wecanclassifysomebasiccaseswithoutcalculatinganythin
5、gbyjustexaminingoneobviousrule:Ifthesuperpositionofthestrainfieldsofdislocationsadduptovaluesofthecompressiveortensilestrainlargerthanthoseofasingledislocations,theywillrepulseeachother.Ifthecombinedstrainfieldislowerthanthatofthesingledislocation,theywillattracteachother.2021/2/78
6、Thisleadstosomesimplecases:1.Arbitrarilycurveddislocationswithidenticalbonthesameglideplanewillalwaysrepeleachother.2021/2/792.ArbitrarydislocationswithoppositebvectorsonthesameglideplanewillattractandannihilateeachotherEdgedislocationswithidenticaloroppositeBurgersvectorbonneighbo
7、ringglideplanesmayattractorrepulseeachother,dependingontheprecisegeometry.Thebluedoublearrowsinthepicturebelowthusmaysignifyrepulsionorattraction.2021/2/710ThegeneralformulafortheforcesbetweenedgedislocationsinthegeometryshownaboveisFx=?[Gb2/2p(1–n)]?·?[x·(x2–y2)/(x2+y2)2]Fy=?[Gb2/
8、2p(1–n)]?·[y·(3x2+y2)/(x2+
