Investigation Of Deformation And Recrystallization Behavior As Well As Texture Of High Purity Aluminum Foil

The plastic deformation, recrystallization behavior and texture development ofhigh purity aluminum foil, which is produced in laboratory or industry, issystematically investigated with optical microscopy (OM), X-Ray diffraction, SEM,TEM and EBSD. The development of deofrmation texture and microstructure,recrystallization grain growth are also numerically simulated. The following resultsare included in the present dissertation:ⅰ. The influence of initial cold-rolling textures on the final recrystallization texturesof high purity aluminum is experimentally and numerically investigated to explorethe relationship between initial and final Cu and S deformation texture, whichfavors the formation of recrystallization cube texture. The results show that theinitial rotated cube texture favors the formation of S deformation texture, whichmeans that rotated cube texture should be developed after hot rolling andintermediate annealing.ⅱ. The dynamic plastic flow curve and Z parameter criterior for dynamicrecrystallization of high purity aluminum are experimentally investigated withGleeble1500. It is found that for 99.992% aluminum, dynamic recovery occurswhen lnZ＞28, discontinuous recrystaUization occurs when lnZ＜21 and continuousrecrystallization occurs when 21＜lnZ＜28. The dynamic plastic flow curvetogether with the microstructure analysis show that the mechanism for dynamicrecrystallization of high purity aluminum is subgrain coalesce.ⅲ. Due to the failure of EBSD in heavily deformed materials, the feasibility ofsubstituting EBSD based GBCD analysis with macro-ODF based GBCD analysis.And the relationship between GBCD and final cube recrystallization cube textureis established.ⅳ. The thermo-dynamical mechanism for influence of trace impurity Fe and Be, Y onthe recrystallization behavior and texture of high purity aluminum are investigatedwith experimental and theoretical analysis, which is the base for control ofrecrystallization behavior and texture of high purity aluminum.ⅴ. The feasibility of strengthening cube texture by changing the existing states ofimpurity Fe with final annealing is investigated, and the technique ofstrengthening cube texture by multi-stage annealing is proposed.ⅵ. The feasibility of controlling recrystallization behavior is numerically investigate with Monter Carlo model.The conclusions such as Z parameter criterior for dynamic recrystallization, theformation of rotated cube oriented shear band and shear deformation and so on,provide some guidence on the production of high purity aluminum foil with strongcube texture for high voltage electrolytic capacitor. And the techniques of hightemperature hot rolling, multi-stage annealing and addition of trace element aresuggested.