135°周向轧制对高纯铌组织均匀性的优化

Optimization of 135° Clock-Rolling for Microstructure Uniformity of High-Purity Niobium

摘要:

传统工业上获取铌板多采用单向轧制(Unidirectional-Rolling)，该工艺下获得的铌板在晶粒尺寸和织构分布上常表现出强烈的不均匀性，导致其在现代工业的使用上具有一定局限性。本实验采用135°周向轧制(135° Clock-Rolling)和单向轧制获得铌板，研究了两种工艺条件下获得的铌板在厚度方向上的组织差异。实验结果表明，135°周向轧制有助于减小高纯Nb板材在厚度方向上的织构梯度。此外，135°周向轧制工艺条件下可以获得具有更高{001}择优取向程度的铌板，且再结晶后，仍然具有较强的{001}择优取向，该织构的占优有助于获得微观组织更均匀的铌板，本实验的显微硬度曲线、再结晶组织显微表征、储存能的半定量计算结果都印证了这一点。还有一点值得注意，相比于单向轧制，135°周向轧制下获得的Nb板材在厚度方向上{111}、{100}取向的储存能差异较小，不会显示明显的能量梯度，这一点同样有助于对高纯铌组织均匀性的优化。

Abstract:

In traditional industries, niobium plates are usually obtained by Unidirectional-Rolling. The niobium plates obtained by Unidirectional-Rolling often show strong unevenness in grain size and texture distribution, which leads to their use in modern industries. The above has certain limitations. In this experiment, 135° Clock-Rolling and Unidirectional-Rolling were used to obtain niobium plates, and the differences in the thickness direction of the niobium plates obtained under the two process conditions were studied. The results show that 135° Clock-Rolling can help reduce the texture gradient of the high-purity niobium sheet in the thickness direction. In addition, niobium plates with a higher degree of {001} preferred orientation can be obtained under the conditions of 135° Clock-Rolling process, and after recrystallization, they still have a strong {001} preferred orientation. This texture The dominance of niobium helps to obtain a more uniform niobium plate, which is confirmed by the microhardness curve, microscopic characterization of recrystallized structure, and semi-quantitative calculation results of storage energy in this experiment. It is also worth noting that compared to Unidirectional-Rolling, the niobium plate obtained under 135° Clock-Rolling has a smaller difference in the storage energy of {111} and {100} orientations in the thickness direction, and does not show a significant energy gradient. This also helps to optimize the uniformity of high-purity niobium.