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Journal of the Korean Ceramic Society 1999;36(11): 1261. |
$Al_2O_3-SiC$ 복합재료의 상압소결시 치밀화에 미치는 SiC 원료분말의 크기영향 |
채기웅 |
호서대학교 신소재기계공학부 |
Effect of SiC Particles Size on the Densification of $Al_2O_3-SiC$ Composite During Pressureless Sintering |
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ABSTRACT |
Effect of SiC particle size of the densification of Al2O3-SiC composite during pressureless sintering was investigated. Two types of SiC powders having average particle size of 0.15${mu}{textrm}{m}$ and 3${mu}{textrm}{m}$ were used. Densification rate of the specimen containing 0.15${mu}{textrm}{m}$ SiC particles was slower than that of the specimen containg 3${mu}{textrm}{m}$ SiC particles. Although the relative density of the specimen containing 0.15${mu}{textrm}{m}$ SiC particles was below 90% of theoretical density after sintering at 155$0^{circ}C$ the complete closure of open pores occurred. Therefore full densification could be obtained by subsequent HIP. On the other hand in the specimen containing 3${mu}{textrm}{m}$ SiC particles the complete closed pore was observed at 95% of theoretical density. Such a fast pore closure in the specimen containing 0.15${mu}{textrm}{m}$ SiC particles is likely to occur as a result of dense reaction layer formation on the specimen surface which is attributed to the high reactivity of small size particles with sintering atmosphere. |
Key words:
Pressureless sintering, Closed pore, Reaction layer, HIP |
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