新型高强铝合金高温平面压缩与退火微观组织和织构

Microstructure and Texture of New High-Strength Aluminum Alloy during Hot Planar Compression and Annealing Processes

摘要:

采用热力模拟平面压缩实验和电子背散射衍射(EBSD)组织分析测试方法，研究了新型Al-Zn-Mg-Cu高强铝合金热压缩变形以及退火微观组织和织构。结果表明，在变形温度为350 ℃，应变速率为0.1 s-1的条件下，合金微观组织演变机理为动态回复和大应变几何动态再结晶，出现旋转立方织构{001}< >和黄铜织构{111}<110>，分别沿着α-取向线和β-取向线分布；退火后旋转立方织构减少，黄铜织构增多，旋转立方织构沿着α-取向线向黄铜织构转变。在变形温度为420 ℃，应变速率为0.1 s-1的条件下，合金变形组织较均匀，再结晶晶粒分布在变形剧烈的晶界或三角晶界处，出现的织构种类主要有旋转立方织构{110}< >、黄铜型{011}<211>织构；退火过程中发生亚动态再结晶，旋转立方织构强度增强，黄铜型{011}<211>织构有向高斯织构方向移动的趋势

Abstract:

Microstructure and texture of new Al-Zn-Mg-Cu high-strength aluminum alloy during hot planar compression deformation and annealing processes were studied by thermo-mechanical modeling planar compression experiments and Electron Back Scattering Diffraction (EBSD). The results show that the softening mechanism during deformation processes at the temperature of 350 °C and the strain rate of 0.1 s-1 is dominated by dynamic recovery and large strain geometric dynamic recrystallization (GDRX). The Rotated Cube {001} < > and the Brass {111} <110> aligned to α and β fibers, respectively, appear in the deformed alloy. After the annealing process, the Rotated Cube texture decreases and the Brass texture increases; meanwhile the Rotated Cube texture transforms to Brass texture along the α-fiber. When hot planar compression is up to 80% high reduction at 420 °C and the strain rate of 0.1 s-1, refined grains with high angle grain boundaries locate at the triangle grain boundaries formed by migration and rotation of subgrain boundaries. The Rotated Cube {110} < > and Brass {011} <211> are presented. After the annealing process, the Rotated Cube texture is enhanced, while the Brass texture transforms to Goss texture