高能球磨制备Tb4O7-TiO2纳米复合粉末的研究

Inverstigation of Tb4O7-TiO2 Mixture Powders Prepared by High Energy Ball Milling

摘要:

通过高能球磨技术制备了Tb4O7-18%TiO2 (质量分数，%)纳米尺度复合粉末。采用激光粒度测试仪、X射线衍射（XRD）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对不同球磨时间的混合粉末的微观组织、颗粒与晶粒大小以及晶格畸变量等进行了研究与表征。实验结果表明混合粉末经过高能球磨后其颗粒与晶粒尺寸均达到了纳米级，组织分布均匀。Tb4O7相的衍射峰随球磨时间的增加逐渐宽化且向大角度偏移；TiO2相衍射峰强度逐渐降低，在球磨4h后消失。随球磨时间的增加，颗粒和晶粒的平均尺寸是减小的，球磨初期减小很快，球磨后期减小缓慢，最后趋于一个稳定值。96h球磨后颗粒和晶粒的平均尺寸分别为200nm和95nm，晶格畸变量达到1.35%。本文同时探讨了TiO2相固溶和纳米晶形成原因以及微观组织演变的机制。

Abstract:

The nanocrystalline powders of Tb4O7-18%TiO2 (mass%)were prepared by high energy ball milling. Systematical investigations were carried out on microstructure、grain size、lattice distortion and morphology of the Tb4O7-18%TiO2 milled powders using Laser Particle Analyzer, X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The experiment results showed that the nanocrystalline and nanoparticle powders were synthesized and microstructure was homogeneous.With the increase of ball milling time, the diffraction peaks of Tb4O7 phase broadened gradually and moved to large angles. Meanwhile, the diffraction peaks of TiO2 phase weakened gradually and disappeared after 4h milling. At the initial stage of ball milling, both particle size and crystalline size reduced significantly, then the size reduced slowly and tended to a stable value on the late stage of ball milling. After 96h milling, the average of particle size and crystalline size was 200nm and 95nm respectively. The lattice distortion was up to 1.35%. The reason of solid solution and nanocrystalline formation and the mechanism of microstructure evolution were also discussed in the present work.