Dry-pressing behavior of silicone-coated alumina powders
The dry-press properties of commercial alumina powders coated with an adsorbed layer of siloxane-terminated silicone were tested. The adsorption reaction was characterized using Fourier transform infra-red (FTIR) spectroscopy. The solvent was removed by filtration. Compression and spring-back during...
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Published in | Powder technology Vol. 1998; no. 2; pp. 104 - 108 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
01.08.1998
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Online Access | Get full text |
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Summary: | The dry-press properties of commercial alumina powders coated with an adsorbed layer of siloxane-terminated silicone were tested. The adsorption reaction was characterized using Fourier transform infra-red (FTIR) spectroscopy. The solvent was removed by filtration. Compression and spring-back during dry pressing, and green strength after pressing were measured for the silicone-coated powders, and compared with those of poly(vinyl alcohol)- (PVA-) and paraffin-coated powders. Silicone was a better lubricant and binder than paraffin or PVA. The recovery of silicone-modified powders was greatest, indicating a lower friction coefficient. Green strengths of dry-pressed bars were compared using four-point bend flexure testing. Weibull moduli were calculated using the method of maximum likelihood. Dry-pressed bars made with silicone-coated powder yielded higher Weibull exponent m and characteristic stress sigma sub o . When the silicone was polymerized after pressing, m and sigma sub o increased further. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 content type line 23 ObjectType-Feature-1 |
ISSN: | 0032-5910 |