Influence of Granules Characteristics and Compaction Pressure on the Microstructure and Mechanical Properties of Sintered Alumina |
Yong-Ick Cho, Sang-Gwi Chung, Sung-Yong Cho, Seung-Jai Kim, Nobuhiro Shinohara 1, Masataro Okumiya 1 |
Engineering Research Institute, Chonnam National University 1Research Center, Asahi Glass Co. Ltd. |
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ABSTRACT |
The influence of granules characteristics and compaction pressure on the microstructure and mechanical properties of sintered as a function of slurry dispersion state. The characteristics and the compaction behavior of the spray dried alumina granules considerably affected the microstructure as well as the mechanical properties of the sintered body. In the green bodies formed with granules prepared with a dispersed slurry, the granules with dimple clearly existed and caused pore defects in sintered body. These dimples were clearly present even in the green body prepared at 180 MPa. The pores between the granules were not removed during pressing and sintering, and remained in the sintered body. In contrast, in the granules fabricated from a flocculated slurry, the destroy of granules at the contact points was observed with increasing pressure. Sintered bodies fabricated with fewer defects showed strength increase. For the sample fabricated with flocculated slurry, the pores at the boundaries of granules were small and more irregular shape compared with those of dispersed slurry. |
Key words:
Flocculated slurries, Spray-dried, Alumina, Granule, Weibull distribution |
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