| Project/Area Number |
61550056
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械材料工学
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| Research Institution | Kyoto University |
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Principal Investigator |
SHIMA Susumu Kyoto University Professor, 工学部, 教授 (70026160)
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| Co-Investigator(Kenkyū-buntansha) |
KUROKAWA Tomoaki Kyoto University Associate professor, 工学部, 助教授 (80127076)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1987: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1986: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | ceramic powder / Characteristics of powder / constitutive equation / three-dimensional compaction / compaction criterion / isostatic compaction / 剛塑性有限要素法 / 窒化けい素紛末 / 粉末成形 / 焼結助剤 / 三次元圧縮 |
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| Research Abstract |
The main objective of this study is to carry out three-dimensinal compaction of ceramic powders to investigate their characteristics and thereby to develop constitutive equations or compaction criteria for general stress state. If this could be done, the properties after sintering could be investigated in terms of the compaction criteria.
The three-dimensional compaction was carried out using a ceramic powder (Si3N4), either with or without sintering additives and the characteristics in compaction were discussed. In a low stress range the ceramic powders are said to behave in particular manner, i.e. tapping of the powder particles, fracture of the agglomerates and rearranging of the particles are likely to occur. The following results were obtained.
(1) The powder with sintering additives can be compacted in a lower stress level compared to that without additives.
(2) The compaction criterion apperars to be given by part of ellipsoid in the principal stress space.
(3) The values of the parameters which are included in the criterion are quite dependent on the characteristics of the powders. The relationship between the parameters and the characteristics should be further investigated.
By employing the characteristics and the constitutive equations for the powders, the rigid-plastic finite element analysis of isostatic compaction (CIP) was carried out. The shape of the compacts and distribution of the density in the compacts depended on the characteristics of the powder and also on the strength of the capsule. The compacts after sintering will thus provide different properties depending on the characteristics. This is a very important point in compactin of ceramic powders.
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