کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9636458 | 465855 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Colloidal processing and sintering of nanosized transition aluminas
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Colloidal processing and sintering of nanosized transition aluminas Colloidal processing and sintering of nanosized transition aluminas](/preview/png/9636458.png)
چکیده انگلیسی
The dispersion of nanosized gamma aluminas with high specific surfaces areas (100 m2/g) and primary particle sizes around 20 nm, using polyacrylic acid, has been investigated. The effect of pH and polymer concentration showed that the highest density green bodies were produced using high polymer concentrations (6 wt.%) and pH of 6. Interparticle potential calculations have been made and help explain the underlying dispersion mechanism at least on a qualitative level. The dispersions were then used to slip cast green bodies followed by drying and sintering. The types of gamma alumina powder have been investigated, the pure gamma alumina, doped with MgO and also with the addition of alpha alumina seeds. The high degree of agglomeration of the gamma alumina powders led to very low densities (60%) even the alpha seeded alumina reached only 85% theoretical density. Attrition milling with zirconia media improves both green density and sintered densities significantly with all powders showing sintered densities > 97%. Microstructural analysis on polished and etched surfaces show, however, that the grain sizes are well above 1 μm over 50 times greater than the initial gamma alumina primary particles. A two-step sintering cycle was investigated with the Mg doped powder and average grain sizes around 580 nm were achieved.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Powder Technology - Volume 157, Issues 1â3, 29 September 2005, Pages 100-107
Journal: Powder Technology - Volume 157, Issues 1â3, 29 September 2005, Pages 100-107
نویسندگان
Paul Bowen, Claude Carry, David Luxembourg, Heinrich Hofmann,