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Transparent Hydroxyapatite Ceramics through Gelcasting and Low‐Temperature Sintering
Author(s) -
Varma Harikrishna,
Vijayan Sekhara Pillai,
Babu Sivadasan Suresh
Publication year - 2002
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2002.tb00120.x
Subject(s) - materials science , sintering , scanning electron microscope , crystallite , indentation hardness , ceramic , precipitation , transmission electron microscopy , vickers hardness test , composite material , sol gel , grain size , metallurgy , mineralogy , microstructure , nanotechnology , physics , meteorology , chemistry
Transparent hydroxyapatite (HAP) was prepared by sintering gel‐cast powder compacts at 1000°C for 2 h; the resultant HAP material was studied using X‐ray diffractometry, transmission electron microscopy, scanning electron microscopy, and microhardness measurement. Nanoscale HAP crystallites were prepared using a precipitation method that involved calcium nitrate and ammonium dihydrogen orthophosphate solutions; the preparation was conducted at a temperature of 0°C. The precipitate was gel‐cast and sintered at 1000°C in the form of a transparent ceramic that had a uniform grain size of 250 μm. The maximum Vickers microhardness obtained for a sample sintered at 1000°C was 6.57 GPa. The sintering behavior of gel‐cast samples prepared from high‐temperature‐precipitated HAP was compared with that of material prepared at 0°C.