交叉轧制周期对高纯Ta板变形及再结晶梯度的影响  

Effect of Cross Rolling Cycle on the Deformed and Recrystallized Gradient in High-Purity Tantalum Plate

作　　者：祝佳林 刘施峰[1] 曹宇 柳亚辉 邓超[1,2] 刘庆[1,2] ZHU Jialin;LIU Shifeng;CAO Yu;LIU Yahui;DENG Chao;LIU Qing(College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;Electron Microscopy Center, Chongqing University, Chongqing 400044, China)

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]重庆大学电子显微镜中心,重庆400044

出　　处：《金属学报》2019年第8期1019-1033,共15页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.51421001;51701032~~

摘　　要：采用新的轧制工艺即135°交叉轧制,获得1周期和2周期Ta板。结合XRD、EBSD、显微硬度及TEM等技术,系统研究了1和2周期Ta板不同厚度层晶粒的变形及再结晶行为。结果表明,2周期Ta板沿厚度方向形成了均匀的θ-fiber和γ-fiber混合型织构。此外,2周期Ta板不同厚度层中{111}与{100}晶粒内的储存能分布也更为均匀。通过EBSD和TEM对变形Ta板的微结构进行表征发现,1周期中心层{111}晶粒内出现了许多相互平行的微带及微剪切带,而2周期表面与中心层晶粒发生相对均匀的变形且亚组织呈胞块状。这主要是因为交叉轧制周期的增加显著地提高了位错交互、湮灭和重排的几率,有利于改善晶粒内部组织的均匀性。因此,2周期Ta板退火时表面和中心层再结晶动力学基本保持一致。Cross rolling plays an important role in the production of high-quality tantalum(Ta) sputtering targets, which are crucial in achieving thin films for micro-electronic components. However, the effect of the cross rolling cycle on the microstructure homogeneity is always ignored. Therefore, 1 and 2 cycle samples were obtained by a new approach named a 135° cross rolling. The deformation and recrystallization behavior of high-purity Ta plate then was systematically compared between 1 and 2 cross rolling cycles, aiming to elucidate why the increase of cross rolling cycles can effectively ameliorate the microstructure gradient along the thickness direction. XRD results showed that the 2 cycle sample through the thickness consisted of a relatively homogenous {111} <uvw>([111]//normal direction(ND)) and {100} <uvw>([100]//ND) fibers while texture distribution was extremely uneven for the 1 cycle sample. The stored energy was quantitatively analyzed by X-ray line profile analysis(XLPA) and it was found that the stored ener-gy across the thickness distributed more homogeneously for the 2 cycle sample. Misorientation characteristics of deformed grains with different rolling cycles were analyzed in detail by visualizing the misorientation angle based on an electron backscatter diffraction dataset. Many well-defined microbands and microshear bands occurred in the {111} grain at the center layer for the 1 cycle sample, while it can be effectively destroyed with the increase of the cross rolling cycle and few peaks occurred in the "point to point" plot. Kernel average misorientation(KAM) and grain reference orientation deviation-hyper(GROD-Hyper)further confirmed their differences. Then, micorband and microshear bands were detailedly characterized by TEM, and the analysis based on relative Schmid factor suggested that the primary slip system activated in the {111} grains led to the formation of microbands in the 1 cycle sample, while multiple slip systems appeared to be activated in the 2 cycle sample and deformation was mor

关 键 词：高纯Ta 交叉轧制周期 储存能 微剪切带 再结晶 

分 类 号：TG146.4[一般工业技术—材料科学与工程]