Densification of Alkoxide‐Derived Fine Silica Powder Compact by Ultra‐High‐Pressure Cold Isostatic Pressing
Densification of Alkoxide‐Derived Fine Silica Powder Compact by Ultra‐High‐Pressure Cold Isostatic Pressing
复制标题
超高压冷等静压致密化醇盐二氧化硅细粉压坯
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
G. Jimbo
中科院分区：
文献类型：
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作者：
H. Kamiya;Hisao Suzuki;D. Kato;G. Jimbo
通过对具有受控结构的颗粒进行超高压冷等静压，将醇盐衍生的细二氧化硅粉末的粉末压块固结成高度致密且均匀的结构。通过改变氨的浓度，成功地将由金属醇盐制备的球形和几乎单一尺寸的无定形二氧化硅颗粒的直径控制在9至760 nm的范围内。通过喷雾干燥生产这些粉末的紧密堆积颗粒。在室温下将这些粉末等静压至1 GPa。虽然平均颗粒直径小于100 nm，但压坯的最大相对密度大于理论密度的78%。获得高密度压块的最佳颗粒尺寸在1GPa下为30至300 nm。此外，在这些压块中的模式孔径与颗粒直径的比率小于0.155，这对应于六方密堆积的计算的三颗粒孔道半径的最小比率。颗粒在超高等静压下的粘性变形对压坯的致密化起着重要作用。
Powder compacts of alkoxide-derived fine silica powders were consolidated into a highly dense and uniform structure by ultra-high-pressure cold isostatic pressing of granules with controlled structure. The diameters of spherical and nearly monosized amorphous silica particles, prepared from metal alkoxide, were successfully controlled in the range of 9 to 760 nm by varying the concentration of ammonia. Close-packed granules of these powders were produced by spray drying. These powders were isostatically pressed up to 1 GPa at room temperature. Although the average particle diameter was less than 100 nm, the maximum relative density of the compacts was more than 78% of theoretical density. The optimum particle size to obtain highly dense compacts was in the range of 30 to 300 nm at 1 GPa. Furthermore, the ratio of mode pore diameter in these compacts to particle diameter was less than 0.155, which corresponded to the minimum ratio of calculated three-particle pore channel radii for hexagonal close packing. Viscous deformation of particles under ultra-high isostatic pressure played an important role in the densification of the compacts.