THERELATIONSHIPSBETWEENGLOBALANDEVERYLAYERDE FORMATIONTEXTURESOF70-30BRASSROLLEDBYCROSSS HEARROLLING¥Zhao,Xiang;Zuo,Liang;Zhao,Hong; Liang,Zhide(DeptartmentofMaterialScienceand Engineering,NortheasternUniversity,Shenyang 110006)Abstract:Globalandeverylayerdeformat iontexturesweredescribedandtherelationshipb etweenthemwereinvestigatedbythreedimensiona lorientationdistributionfunction.Itwasfound thatthemacroscopicstatisticalunsymmetryofgl obaltextureisnotthesameasthatofeverylayerte xture,butconsistentwiththatofbesideslowspee droller,theresultswhichwereaddedandaveraged by5layersODFdonotrepresentglobaltexture.Key words:crossshearrollingmacroscopicstatistic alunsymmetrytexturethreedimensionalorientat iondistributionfunction(ODF)1INTRODUCTIONTh eunsymmetricplasticflowproducedbycrossshear rollinginsingledirectonresultsinmacroscopic statisticalunsymmetriesoftextureinglobaland everylayer[1-2],thiskindofunsymmetrycanlead directlythechangeofrolledplateproperty,ther efore,itisimportanttoresearchthemacroscopic statistialunsvmmetriesoftexture.Inthispaper ,theunsymmetriesoftextureinglobalandeveryla yerof70-30brassrolledbycrossshearrollingins ingledirectionarediscribedandtherelationbet wenglobalandeverylayertexturesisinvestigate dbythethreedimentionalorientationdistributi onfunction(ODF).2EXPERIMENTALCommercial70-3 0brass2mminthicknesswasrolledbycrossshearro llinginsingledirectionat90%reductioninthick ness,linearvelocitiesratiooffastandslowspee drollerswas1.28.Thentherolledplatewasdivide dintofivelayersalongrollingplanenormal,from surfacebesideslowroller,eachlayerwasmarkedb y0,1/4,1/2,3/4,1layerrespectively.Severalpi ecesoftestedsheetsweregluedtogetherinaccord ancewithsamerollingdirectiontoformarectangl ebodyinwhichasectionwascutandanarrowwassign edinthesectionasinmeasuredcompositesample{1 11},{200}and{220}threeimcompletepolefigures aremeasuredbytheSchulzmethod[3],20°≤α≤90°,△ α=△β=5°.TheunsymmetricODFswerecalculatedasL max=16[14].UnderthecoordinateOA′B′C′oftheco mpositesample,thecoefficientofODFisWlpmwhic hcanbetransformedintothecoordinateOABCinwhi chRD,TDandNDarecharacteristicdirectionaccor dingtoformula[5]whereα,βandγisEulerangle.OD FcanbecalculatedbymeansofWlmm.①ReceivedSept .5,19943RESULTSTheODFsectionsofcostantψ=35° andψ=145°ineverylayerandglobalof70-30brassr olledbycrossshearrollinginsingledirectionar eshowninFig.1.Itisfoundthatmaintexturesinev erylayerandglobalare{110}<112>whicharethesa measmaintextureof70-30brassrolledbycommonro lling,Fig.1ψ=35°andψ=145°ODFcostantsections ofeverylayerandglobaltextures(a)─01ayer;(b) ─1/4layer;(c)─1/2layer;(d)─3/4layer;(e)─1la yeri(f)─averageof5layersl;(g)─globalbutthei ntensityandscatteringofeverytexturecomponen tin{110}<112>aredifferent,thatis,thereisama croscopicstatisticalunsymmetry.In0,1/4and1/ 2layers,intensityofisweakerthanthatofin3/4a nd1layers,intensityofisstrongerthanthatof[1 12],itisjustcontrarywiththeconditionin1,1/4 and1/2layers.Simulatneously,theunsymmetryof texturebesidefastrollerisstrongerthanthatbe sideslowroller.Theresultaddedandaveragedfro mODFsoffivelayersshowsthatintensityofisstro ngerthanthatofandtherestillisweakermacrosco picstatisticalunsymmetry.ODFsection(Fig.1(g ))calculatecfromcompositesamplerevealsamacr oscopicstatisticalunsymmetryofglobaltexture ,thatisintensityofisweakerthanthatofandtheu nsymmetryisstrongerbutintensityoftextureisw eaker.4DISCUSSIONInthecrossshearrolling,the unsymmetryoflinearvelocitiesbetweenthefasta ndslowspeedrollersformsthecrossshearrolling zone(Fig.2)inwhichshearforcestotheexitandth eentrancedirectionrespectivelyproducedonthe sheetbesidefastandslowrollers,therefore,uns ymmetricplasticflowandmacroscopicstatistica lunsymmetryoftextureareformed.Inbackwardsli pzonetherearetheshearforcestoexitdirectiono nthesheetbesidefastandslowrollers,theycanse paratelyincreaseanddecreaseunsymmetricplast icflowsandthesymmetryoftextureonthefastands lowrollers.Insideofthesheet,differentshearf orceswhichareweakerthanthatofsurfacesareproducedandresultinweakerintensityandtheunsymmetryoftexture.Throughtheunsymmetryin1layeristhestrongest,butthetexturebesidetheslowrol
More abstracts about the THE RELATIONSHIPS BETWEEN GLOBAL AND EVERY LAYER DEFORMATION TEXTURES OF 70-30 BRASS ROLLED BY CROSS