Because calcined alpha alumina ( α -Al 2 O 3 ) inherits the morphology characteristic of milled precursors, it is expected that the α -Al 2 O 3 morphology could be improved by controlling the precursor morphology through the use of different milling processes. The microstructure evolution of the boehmite precursor under different milling treatments (planetary ball milling [PBM] and high-energy ball milling [HEBM]) and its influence on the microstructure of as-synthesized α -Al 2 O 3 were investigated. The experimental results indicate that HEBM has a stronger modification effect in crystallinity, particle size and dispersibility of the boehmite precursor than PBM, which is of great importance to inhibit the formation of the typical worm-like structure of α -Al 2 O 3 . The microstructure of α -Al 2 O 3 was further improved by the introduction of NH 4 BF 4 , NH 4 F and NH 4 Cl as additives. In particular, polygon-like α -Al 2 O 3 particles with a size of 0.5 μm and a good dispersibility were prepared by calcination of the precursor with 30 h of HEBM and 20 wt.% NH 4 BF 4 .

中文翻译：

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研磨处理和添加剂对商用勃姆石前体中α-氧化铝形态演变的影响

因为煅烧的α氧化铝（α-Al 2 O 3）继承了研磨前体的形态特征，所以期望通过使用不同的研磨工艺控制前体形态可以改善α-Al 2 O 3形态。研究了勃姆石前体在不同球磨处理（行星式球磨[PBM]和高能球磨[HEBM]）下的微观结构演变及其对合成的α-Al 2 O 3微观结构的影响。实验结果表明，HEBM在勃姆石前体的结晶度，粒径和分散性方面比PBM具有更强的改性作用，这对于抑制典型的α-Al 2 O 3蠕虫状结构的形成具有重要意义。通过引入NH 4 BF 4，NH 4 F和NH 4 Cl作为添加剂，进一步改善了α-Al 2 O 3的微观结构。特别地，通过用30h的HEBM和20wt。％的NH 4 BF 4煅烧前体来制备大小为0.5μm且具有良好分散性的多边形状α-Al 2 O 3颗粒。