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通过高能球磨技术制备了Tb_4O_7-18Ti O_2(质量分数,%)纳米尺度复合粉末。采用激光粒度测试仪、X射线衍射仪(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形貌组织、颗粒与晶粒大小以及晶格畸变量等进行了研究与表征。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,组织均匀。Tb_4O_7相的X射线衍射峰随球磨时间的增加逐渐宽化且向大角度偏移;Ti O_2相衍射峰强度逐渐降低,在球磨4 h后消失。随球磨时间的增加,颗粒和晶粒的平均尺寸减小,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。96 h球磨后颗粒和晶粒的平均尺寸分别为200和95 nm,晶格畸变量达到1.35%。同时探讨了TiO_2相固溶和纳米晶形成原因以及微观组织演变的机制。
Tb_4O_7-18Ti O_2 (mass fraction,%) nano-scale composite powders were prepared by high-energy ball milling. The microstructure, grain size and grain size of the mixed powders with different ball milling time and the amount of lattice distortion were measured by laser particle size analyzer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) Etc. were studied and characterized. The results showed that the particle size and grain size of the mixed powder reached nanometer level after the high energy ball milling, and the microstructure was even. The X-ray diffraction peak of Tb_4O_7 phase broadened and shifted to a large angle with the increase of ball milling time. The diffraction intensity of Ti O_2 phase decreased gradually and disappeared after 4 h milling. With the increase of ball milling time, the average size of grains and grains decreases, the initial ball milling decreases rapidly, the ball milling decreases slowly and finally reaches a stable value. After 96 h ball milling, the average size of grains and grains were 200 and 95 nm, respectively, and the lattice distortion reached 1.35%. At the same time, the mechanism of the formation of solid solution and nanocrystalline TiO_2 phase and the microstructure evolution were also discussed.