Microstructural and textural evolution of pure titanium during differential speed rolling and subsequent annealing
Microstructural and textural evolution of pure titanium during differential speed rolling and subsequent annealing
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DOI：
10.1007/s10853-014-8019-4
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发表时间：
2014-01
影响因子：
4.5
通讯作者：
Xinsheng Huang;Kazutaka Suzuki;M. Yuasa;Y. Chino
中科院分区：
文献类型：
--
作者：
Xinsheng Huang;Kazutaka Suzuki;M. Yuasa;Y. Chino
用电子背散射衍射仪研究了纯钛在500℃差速轧制(DSR)及随后的退火过程中的组织和织构演变。孪生只发生在DSR的初始阶段，进一步的变形以位错滑移为主。轧制时的组织特征是大的变形晶粒，它是材料的主要成分，一些动态再结晶(DRXed)晶粒主要存在于剪切带区域。在DSR过程中，轧制织构发生了显著的变化，从横向(TD)分裂织构(基极在±40°处大幅度倾斜)到单峰基面织构。这种织构变化在DSR后期加速，可能是由于基底滑移活动增强导致变形颗粒的逐渐晶格旋转所致。退火热处理后，基面织构重新转变为TD-Split织构，基极倾斜±25°，这是由于具有TD-Split织构的DRXed晶粒消耗了基面取向的形变颗粒。随之而来的广泛的晶粒长大使a轴的取向由平行于Td方向变为平行于轧制方向，这是择优生长的结果。
The microstructural and textural evolution of pure titanium during differential speed rolling (DSR) at 500 °C and subsequent annealing were investigated using electron backscattered diffraction analysis. Twinning only occurs in the initial stage of DSR, and further deformation is dominated by dislocation slip. The as-rolled microstructure is characterized by large deformed grains, which form a major component of the material, and some dynamically recrystallized (DRXed) grains mainly existing in shear band regions. A dramatic change in the rolling texture, from the transverse direction (TD) split texture with basal poles largely tilted at ±40° to the single-peak basal texture, occurs during DSR. This change in texture is accelerated during the late stage of DSR and may be attributed to the gradual lattice rotation of deformed grains caused by enhanced basal slip activity. The basal texture changes back to the TD-split texture with basal poles tilted at ±25° after annealing due to consumption of deformed grains with basal orientations from DRXed grains with the TD-split texture. Subsequent extensive grain growth changes the orientation of thea-axis from parallel to the TD to parallel to the rolling direction, which is the result of the preferential grain growth in that direction.