高纯钽交叉轧制过程中微观结构和织构梯度的演变  

Evolution of texture gradient and microstructure of high purity tantalum in clock-rolling process

作　　者：毛宇成 刘施峰[1] 范海洋[1] 刘庆[1] 

机构地区：[1]重庆大学材料与科学工程学院,重庆400044

出　　处：《电子显微学报》2017年第1期7-13,共7页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金青年基金资助项目(No.0211002321111)

摘　　要：高纯钽板在交叉轧制过程中,通过控制轧制的道次,得到了70%,82%和87%变形量的样品。应用X-射线衍射(XRD)技术测量了轧制样品1/8厚度层,1/4厚度层和中间层的宏观织构,并对样品沿厚度方向上的变形组织与微织构进行电子背散射衍射(EBSD)表征。结果表明,随着交叉轧制变形量的增加,{111}〈uvw〉和{100}〈uvw〉取向晶粒的取向分裂程度增加,并且{111}取向的晶粒分裂程度高于{100}取向的晶粒。变形量为70%时,高纯钽板沿厚度方向存在强烈的微观组织和织构梯度,中间层具有强烈的{111}〈uvw〉取向晶粒,而1/8厚度层主要为{100}〈uvw〉取向。随着变形量增加,高纯钽板沿厚度方向的微观组织和织构均匀性得到改善。当变形量达到87%时,表面和中心的{100}〈uvw〉和{111}〈uvw〉取向晶粒都为长条状且交互分布在一起,使得钽板沿厚度方向织构梯度得到减弱,同时获得均一的晶粒尺寸。The samples of high-pure tantalum were obtained by controlling roll-passes with deformation at 70%,82% and 87% in the clock-rolling process. X-ray diffraction（ XRD） technology was applied to measure the macro-texture of high-pure tantalum at the surface layer,a quarter of layer and the middle tier. At the same time,the electron back scattered diffraction（ EBSD） technology was used to reveal the evolution of the deformation texture and microstructure along the thickness-direction. The results show that the degrees of orientation-divide in the { 111} 〈uvw〉and { 100} 〈uvw〉textures both increase with the accumulation of cross-rolling deformation,and the degree of orientation-divide in the { 111} 〈uvw〉texture is higher than that in the { 100} 〈uvw〉texture. When the rolling reduction reaches to 87%,the { 100} 〈uvw〉texture and { 111} 〈uvw〉texture at the surface and center layers are in strip shape and interactive distribution in each other,which can reduce the texture gradient of tantalum-plate along the thickness-direction and obtain the uniform grain size.

关 键 词：交叉轧制 X-射线衍射(XRD)技术 电子背散射衍射(EBSD)技术 织构梯度 取向分裂 

分 类 号：TG339[金属学及工艺—金属压力加工] TG166.7