Fabrication of submicron α-Al2 O3 by the transformation of microcrystalline γ-Al2 O3 under high-pressure
-
摘要: 采用微米γ-Al2O3为原料,利用国产铰链式六面顶压机,在5 GPa压强下,经不同的温度和保温时间,实现了由γ-Al2O3向α-Al2O3的相转变。X射线衍射分析结果表明,得到的粉体和块体材料中均仅含α-Al2O3单相;扫描电镜结果显示合成的α-Al2O3最小晶粒尺寸为80 nm。在5 GPa压强、800 ℃条件下合成的样品平均晶粒尺寸为340 nm,实现了用微米γ-Al2O3高压相变制备亚微米α-Al2O3。与常压烧结方法相比,采用高温高压烧结,可在600 ℃实现γ-Al2O3向α-Al2O3的转变,显著降低α-Al2O3材料的合成温度。Abstract: Microcrystalline γ-Al2O3is used as raw material to prepare α-Al2O3from γ-Al2O3using the hinge-type cubic press under the pressure of 5 GPa with different temperatures. The results of X-ray diffraction analysis show that the obtained powders and bulk materials are pure α-Al2O3phase. The scanning electron microscope analysis shows that the minimum grain size of the α-Al2O3is about 80 nm and the average grain size of the α-Al2O3synthesized under the pressure of 5 GPa and the temperature of 800 ℃ is 340 nm. Experimental results show that the submicron α-Al2O3is fabricated by high pressure phase transformation of microncrystalline γ-Al2O3. Compared with the normal pressure sintering method, the complete phase transformation from γ-Al2O3to α-Al2O3can be achieved at 600 ℃ by high pressure sintering, which obviously reduces the synthesis temperature of α-Al2O3materials.
-
Key words:
- high temperature and high pressure /
- gamma alumina /
- alpha alumina /
- abrasive
点击查看大图
计量
- 文章访问数: 94
- HTML全文浏览量: 9
- PDF下载量: 6
- 被引次数: 0