Study On The Recrystallization Exture And Earing Behavior Of L-MG Loy

Al-Mg alloys are of great potential as structural materials for their appreciatedproperties, such as low density and high specific strength.THowever, because of texturecharacteristics, the occurrence of earing during deep drawing of a texture sheet affects theproduct yield and production efficiency resulting in the waste of resources and costs.Therefore, it is essential to control the ratio of recrystallization texture and deformationtexture of alloy sheet for reducing the earing ratio.The materials used in the present investigation were CC AA5005, CC AA5182andDC AA5182aluminum alloy sheets. The hot bands of aluminum alloys were annealed atdifferent temperature and then cold rolled to different reductions. Texture measurementswere performed for the cold rolled and annealed sheets by X-ray diffraction. The volumefractions of the texture components were calculated by an improved integration method.The mathematical relationship was established between the texture volume fractions withannealing time and annealing temperature. The evolution of recrystallization textureduring rolling and annealing were analyzed quantitatively by using the integral method.Based on the Man's theory for angular dependence of the r-value, a formula was deducedon relationship between the earing profile and texture parameters which quantified theeffect of crystallographic texture on earing profile. The material parameters in theformula were determined by simulation analysis the earing profiles of four ears, six earsand eight ears for polycrystalline aluminum alloy.The recrystallization cube textures were stronger with increasing the annealingtemperature and annealing time during DC AA5182aluminum alloy isothermalannealing at temperature range from260to343°C for2s to3h. The change of thetexture volume fraction followed the JMAK equation during the isothermal annealingprocess. The recrystallization texture is mainly composed of R, cube and Goss orientation.At the same annealing temperature, the cold rolled alloy with pre-recovery processingcomprised more of the R texture and weaker cube texture than without pre-recoveryannealing treatment of cold rolled aluminum alloy.T The recrystallization texture of aluminum alloy was strongly affected by colddeformation.The strength of the cube component decreased while the R componentincreased with the increasing of deformation for CC AA5005aluminum alloy. Therecrystallization texture was composed with a strong R texture component, a weak cubeand P{011}<455> texture component when theTcoldTT TTdeformationTreached93.1%. Aftercomplete recrystallization, the strength of the cube texture, R texture and Goss textureincreased with the increasing of deformation for DC AA5182aluminum alloy.The strength of the β fiber component of CC AA5182aluminum alloy increasedwith the cold rolling deformation increasing.The maximum earing value was about9%when the cold rolling reduction reached90%. DC AA5182aluminum alloy sheetproduced90ears due to the strong cube recrystallization texture. The strength of cubetexture decreased, whereas the strength of β fiber component increased with the rollingdeformation increasing, leading to the90°earing value decreasing and the45°earingvalue increasing. The minimum earing ratio was about3.5%when the cold rollingreduction reached83%because of balance for two types of textures. Beforerecrystallization, β fiber texture component, Goss texture component and remaining cubecomponent were included in DC AA5182aluminum alloy. After completerecrystallization the change of texture was slight, whereas the45°earing ratio was lowerthan before recrystallization. The0°earing ratio decreased with the process ofrecrystallization. The texture of CC aluminum alloy sheet was β fiber components,moreover, the texture did not change during recovery. After complete recrystallization,CC aluminum alloy sheet formed the R orientation and mainly produced the45°earing.The earing ratio decreased with the process of recrystallization.The earing profile of the polycrystalline aluminum alloy were predicted by usingcomputer simulation techniques and compared with the measurement results. It is notedthat the simulation earing profile was in accordance with the measurement in terms ofearing location, size and shape. And the higher the number of terms reserved, the closerthe earing profiles which were simulated with the experiment results, verifying theaccuracy of the formula.