Development of Aluminum Alloy Sheet with Excellent Formability through Texture Control by Asymmetric rolling

通过非对称轧制织构控制开发具有优异成形性的铝合金板

• 批准号: 12555199
• 负责人: SAKAI Tetsuo
• 金额: $ 8.38万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12555199/
• 关键词: asymmetric rolling; differential speed rolling; shear deformation; shear texture; aluminum alloy; r-value; press formability; grain refinement; 高成形性アルミニウム合金板

Large shear strain exceeding 4.0 was successfully introduced in 1050 aluminum sheet by 2-pass differential roll speed rolling. The shear texture of which main components were {111}<110>, {112}<110> and {001}<110> prevailed throughout the thickness, and conventional rolling texture such as {112}<11> or {123}<634> orientation was not observed in any part of thickness. The intensity of shear component increased with shear strain. The rolling direction of the second pass exerts a little effect on the deformation texture. After recrystallization annealing, shear texture components are retained.The r-value of 1050 aluminum sheet was not affected by roll speed ratio, however Δr slightly decrease with increasing roll speed ratio. The pass schedule of 2-pass differential speed rolling slightly had an influence on r-value which becomes maximum in 2-pass equal reduction rolling. The r-value of the sheet rolled by 2-pass reverse shear rolling, in which the sheet was turned 180 degree around its ND … More axis before second pass rolling, was slightly higher than that of 2-pass unidirectional shear rolling, in which the sheet was turned 180 degree around its TD axis before second pass.The r-value of 5182 aluminum alloy sheet increased with roll speed ratio, and was 0.9 at the roll speed ratio of 1.8. The sheet rolled by conventional (symmetric) rolling without lubrication attained the r-value of 0.85 that is higher than of commercial 5182 alloy sheet. Even in conventional rolling, large shear strain is introduced near the surface of rolled sheet when rolling is conducted under high friction condition. Near the surface of conventionally rolled sheet, shear texture of which <111> axis is just parallel to the ND axis develops, whereas <111> axis slightly inclines towards rolling direction in differential speed rolling. The small difference between r-values of conventionally rolled sheet and asymmetrically rolled sheet is probably due to this difference of <111> axis direction. However the these r-values are higher than that of the sheet rolled by conventional rolling with lubrication. The effect and usefulness of shear strain on the r-value was confirmed.The recrystallized grain size decreased with increasing roll speed ratio. The smallest grain size attained in the present study was 4μm. The strength also inereased with roll speed ratio without loss of ductility.We have succeeded in improving press formability and strength of aluminum alloy sheet by differential speed rolling, bay which shear deformation can be introduced throughout the thickness of rolled sheet. It is proved that the differential speed rolling is promising process for improving physical and mechanical properties of rolled sheet by microstructure and texture control. This process can be applied not only for aluminum alloy but also for other metallic materials. Less

采用2道次差速轧制成功地在1050铝板材上引入了大于4.0的大剪切应变。主要成分为{111}-lt；110->t；、{112}-lt；110->t；和{001}-lt；110->t；的剪切织构在整个厚度范围内占优势，在厚度的任何部位都没有观察到{112}-lt；11->t；或{123}-lt；634->；取向的常规轧制织构。剪切分量的强度随着剪切应变的增大而增大。第二道次的轧制方向对变形织构影响不大。再结晶退火后，剪切织构成分保持不变。1050Al板材的r值不受轧速比的影响，但Δr随轧速比的增加而略有下降。2道次差速轧制的道次制度对r值影响较小，在2道次等压下r值最大。2道次反向剪切轧制中，板材绕ND…旋转180度时的r值5182铝合金板材的r值随着轧速比的增大而增大，当轧速比为1.8时，r值为0.9。常规(对称)轧制无润滑轧制的r值为0.85，高于商品化的5182合金板材。即使在常规轧制中，在高摩擦条件下轧制时，在轧件表面附近也会产生较大的剪切应变。在常规轧制板材表面附近，&lt；111&gt；轴与ND轴平行的剪切织构发育，而差速轧制时&lt；111&gt；轴略微向轧制方向倾斜。常规轧制和非对称轧制的r值之间的微小差异可能是由于&lt；111&gt；轴方向的差异造成的。但这些r值均高于常规润滑轧制的r值。证实了剪切应变对r值的影响和作用，再结晶晶粒度随轧速比的增大而减小。本研究获得的最小晶粒度为4μm，强度也随着轧速比的增加而提高，而塑性没有损失。通过差速轧制，可以在整个轧制厚度范围内引入剪切变形，从而成功地提高了铝合金板材的冲压成形性和强度。结果表明，差速轧制可以通过控制组织和织构来改善轧制后板材的物理力学性能，是一种很有前途的工艺。该工艺不仅适用于铝合金，也适用于其他金属材料。较少

项目成果

T.Sakai, S.Hamada, Y.Saito: "Improvement of the r-value in 5052 Aluminum Alloy Sheets Having Through-Thickness Shear Texture by 2-Pass Single-Roll Drive Unidirectional Shear Rolling"Scripta Materialia. 44-11. 2569-2573 (2001)

T.Sakai、S.Hamada、Y.Saito：“通过 2 道次单辊驱动单向剪切轧制提高具有全厚度剪切织构的 5052 铝合金板的 r 值”Scripta Materialia。

T.Sakai, K.Yoneda, Y.saito: "Control of Through-Thickness Shear Texture by Asymmetric Rolling"Materials Science Forum. 396-402. 309-314 (2002)

T.Sakai、K.Yoneda、Y.saito：“通过不对称轧制控制全厚度剪切纹理”材料科学论坛。

T.Sakai, S.Hamada, Y.Saito: "Improvement of the r-value in 5052 Alloy Sheets Having Through-Thickness Shear Texture by 2-Pass Single-Rool Drive Unidirectional Shear Rolling"Scripta Materialia. Vol.44. 2569-2573 (2001)

T.Sakai、S.Hamada、Y.Saito：“通过 2 道次单辊驱动单向剪切轧制改善具有全厚度剪切纹理的 5052 合金板的 r 值”Scripta Materialia。

T.Sakai, S.Hamada, Y.Saito: "Foemation of Shear Texture in A 5052 Sheet by Single-Roll Drive Warm Rolling"Aluminum Alloys (Proceedings of ICAA-6). 1161-1166 (1998)

T.Sakai、S.Hamada、Y.Saito：“单辊驱动温轧制 5052 板材中剪切纹理的形成”铝合金（ICAA-6 会议记录）。