轧制方向对ZIRLO合金织构及变形机制的影响

Effect of rolling direction on texture and deformation mechanism of ZIRLO alloy

以核用Zr-Sn-Nb系ZIRLO合金为研究对象,对其沿板的长度和宽度方向轧制后的组织及织构演变进行研究,并采用电子背散射衍射和晶内取向差转轴方法,对轧制过程中开启的滑移系进行了分析并统计了不同变形量下各滑移系的占比情况。结果表明:沿不同方向轧制并未改变织构类型,但织构特征存在一定的差异。沿长度方向轧制形成近似椭圆状的双峰织构,而沿宽度方向轧制最终形成更加集中且对称的双峰织构。变形量不同,主导的变形模式不同。小变形量时柱面滑移主导变形,随着变形量的增大,基面和锥面滑移的活性增强。沿板宽方向轧制时产生更多的{1012}孪晶协调变形且大变形量下基面和锥面滑移的数量多于长度方向。

The microstructure and texture evolution of ZIRLO alloy of Zr-Sn-Nb series for nuclear use after rolling in the length and width directions were studied.The slip systems activated in the rolling process were analyzed and the proportion of each slip system with different deformations was calculated by electron backscatter diffraction(EBSD)and in-grain misorientation axis(IGMA)methods.The results show that rolling in different directions does not change the texture type,but there are certain differences in texture characteristics.The nearly elliptical bimodal texture is formed when rolling in the length direction,while the more concentrated and symmetrical bimodal texture is formed when rolling in the width direction.The dominant deformation mode varies depending on the deformation.Prismatic slip dominates the deformation with small deformation,and the slip activities of basal slip and pyramidal slip increase with the increase of deformation.More{1012}twins are generated to coordinate deformation when rolling along the width direction and the numbers of basal and pyramidal slip are more than that in the length direction under large deformation.