Al-Mg Alloy Sheet of Excellent Formability for Automobile

在面心立方金属和合金中，（111）面平行于轧制面排列的再结晶织构很少见到。汽车用Al-Mg和Al-Mg-Si系合金的Lankford值可望得到提高，只要发展（111）再结晶织构。在具有（001）[110]剪切织构的铝板表层形成了由近（123）[143]和近（123）[931]取向组成的再结晶织构。这些取向的四个{111}极之一位于（111）极图的中心附近。由于剪切织构构成了铝热轧织构的一个组成部分，因此可以预测在再结晶温度以下温轧的Al-Mg合金中（001）[110]剪切织构的发展。在这项研究中，热轧板的Al-4.0Mg，在250 ℃ ~ 300 ℃温轧至85%时，对5 mm厚的Al-4.0Mg-0.1Fe-0.1Si和Al-5.5Mg合金进行了（111）再结晶织构和沿厚度方向向R取向的织构梯度的形成以及（111）织构的影响。研究了再结晶织构对r值提高的影响。（111）[110]剪切织构形成到表面以下25-30%的内层，在280 ℃和300 ℃轧制的Al-4.0Mg-0.1Fe-0.1Si和Al-5.5Mg合金中，退火后的（111）再结晶织构无论如何被描述为（111）[110]。在半厚度内到具有（111）[110]剪切织构的片材的中心的大范围内产生取向。获得了高于1.3的平均r值，但其在轧制平面内的各向异性比工业产品大得多。

A recrystallization texture whose (111) plane is arranged parallel to the rolling plane has scarcely been found in fcc metals and alloys. The improvement of Lankford value in Al-Mg and Al-Mg-Si alloys for automobile can be expected, if the (111) recrystallization texture is developed. A recrystallization texture consisting of near (123) [143] and near (123) [931] orientations was formed in the surface layr of aluminum sheet having the (001) [110] shear texture. One of the four {111} poles of those orientations lies near the center of (111) pole figure. Since the shear texture constitutes a component of hot-rolling textures in aluminum, the development of the (001) [110] shear texture can be predicted in the Al-Mg alloy warm-rolled just below the recrystallization temperature. In this study hot-rolled plates of Al-4.0Mg, Al-4.0Mg-0.1Fe-0.1Si and Al-5.5Mg alloys of 5mm in thickness were warm-rolled to 85% in the temperature range from 250ﾟC to 300ﾟC.The formation of a (111) recrystallization texture and the through thickness texture gradient to the R orientation as well as the effect of the (111) recrystallization texture on the improvement of r value were examined. A (111) [110] shear texture was formed up to the inner layrs 25-30% below the surface, both in the Al-4.0Mg-0.1Fe-0.1Si and Al-5.5Mg alloys rolled at 280ﾟC and 300ﾟC.After annealing a (111) recrystallization texture to be described anyhow as a (111) [110] orientation was generated with a large spread within the half thickness to the center of the sheet having the (111) [110] shear texture. An average r value higher than 1.3 was obtained but its anisotropy within the rolling plane was much larger than industrial products.