TY - JOUR
T1 - Ultrastructural observation of hydroxyapatite ceramics with preferred orientation to a-plane using high-resolution transmission electron microscopy
AU - Zhuang, Zhi
AU - Miki, Takuya
AU - Yumoto, Midori
AU - Konishi, Toshiisa
AU - Aizawa, Mamoru
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2012
Y1 - 2012
N2 - The dense hydroxyapatite (HAp) ceramics with preferred orientation to a-plane were fabricated using composite powders of single-crystal apatite fibers (AF) and wet-synthesized apatite gels (AG). AF was synthesized by homogeneous precipitation method. The composites of AF and AG were prepared as the following process. Aqueous (NH4)2HPO4 solutions were added into the AF slurry with the amount of 1 mass%. In addition, aqueous Ca(NO3)2 solutions were added dropwise to the slurry to precipitate the AG on the AF at room temperature, and then aged at room temperature for 24 h with stirring. The dried powders were uniaxially pressed at 200 MPa of compaction pressure and then fired at 1300 °C for 5 h. All the resulting ceramics were identified with HAp single phases. The (100), (200) and (300) reflections which correspond to a-plane were more intense than those of a standard HAp ceramics. With increasing the additive amount of AG, the orientation degree of a-plane decreased, and the relative density increased. Furthermore, the ultrastructure of the resulting ceramics was examined by highresolution transmission electron microscopy. The selected area electron diffraction patterns showed clear spots corresponding to [110] zone axis direction of HAp crystal with high crystallinity. The lattice spacings of crystal grains were determined to be 0.34 nm or 0.68 nm which corresponds to the lattice constant of (002) or (001) plane of HAp crystal. Therefore, the resulting ceramics were HAp single phases with preferred orientation to a-plane.
AB - The dense hydroxyapatite (HAp) ceramics with preferred orientation to a-plane were fabricated using composite powders of single-crystal apatite fibers (AF) and wet-synthesized apatite gels (AG). AF was synthesized by homogeneous precipitation method. The composites of AF and AG were prepared as the following process. Aqueous (NH4)2HPO4 solutions were added into the AF slurry with the amount of 1 mass%. In addition, aqueous Ca(NO3)2 solutions were added dropwise to the slurry to precipitate the AG on the AF at room temperature, and then aged at room temperature for 24 h with stirring. The dried powders were uniaxially pressed at 200 MPa of compaction pressure and then fired at 1300 °C for 5 h. All the resulting ceramics were identified with HAp single phases. The (100), (200) and (300) reflections which correspond to a-plane were more intense than those of a standard HAp ceramics. With increasing the additive amount of AG, the orientation degree of a-plane decreased, and the relative density increased. Furthermore, the ultrastructure of the resulting ceramics was examined by highresolution transmission electron microscopy. The selected area electron diffraction patterns showed clear spots corresponding to [110] zone axis direction of HAp crystal with high crystallinity. The lattice spacings of crystal grains were determined to be 0.34 nm or 0.68 nm which corresponds to the lattice constant of (002) or (001) plane of HAp crystal. Therefore, the resulting ceramics were HAp single phases with preferred orientation to a-plane.
KW - High-resolution transmission electron microscopy
KW - Hydroxyapatite ceramics
KW - Microstructure
KW - Preferred orientation
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U2 - 10.1016/j.proeng.2012.03.019
DO - 10.1016/j.proeng.2012.03.019
M3 - Conference article
AN - SCOPUS:84888584400
VL - 36
SP - 121
EP - 127
JO - Procedia Engineering
JF - Procedia Engineering
SN - 1877-7058
T2 - 2011 IUMRS International Conference in Asia, ICA 2011
Y2 - 19 September 2011 through 22 September 2011
ER -