Mechanism of superplastic deformed transparent hydroxyapatite |
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| Authors: | J Yun B N Kim Y H Han H W Son S Kim |
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| Affiliation: | 1. Department of Nano Materials EngineeringKyungnam University, Masanhappo-gu, Changwon, Gyeongnam 631–701, Republic of Korea.;2. National Institute of Materials ScienceAdvanced Ceramics Group, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan;3. School of Materials Science and EngineeringYeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk 712-749, Korea |
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| Abstract: | Superplastic deformed hydroxyapatite (HA) samples were examined by TEM to elucidate the deformation mechanism in the HA. The present paper was to study the main mechanism of the superplastic behaviour of nanocrystalline transparent HA with a mean grain size of 170 nm fabricated by spark plasma sintering, which has exhibited superplasticity at temperatures ranging from 950 to 1050°C with a maximum elongation of 486% at 1000°C at an initial strain rate of 1·0×10?4 s?1. The post-deformation microstructure of HA indicated that activated dislocation motion assisted grain boundary sliding was the predominant mechanism of superplastic flow with the values of the stress exponent, 4 to 5, according to a theoretical model of interface reaction controlled creep. Unexpectedly, no dislocation was observed by TEM. |
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| Keywords: | Spark plasma sintering Hydroxyapatite Superplasticity Deformation mechanism |
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