Effect of morphology on densification study of nano – hydroxyapatite

Abstract

Spherical, rod and fibrous morphology of Hydroxyapatite (HA) nanoparticles were considered to understand the densification behaviour at high temperature. Thermal analysis of as-received HA nanoparticles confirmed the phase transformation temperature for different morphologies. The phase stability was strictly deepened on morphology of HA nanoparticles. X – ray diffraction (XRD) pattern and Fourier transformation Infrared (FTIR) was studied to evaluate the crystal structure, phase and purity for different calcined powders and their sintered specimens. Spherical, rod and fibrous nano-HA morphology were stable up to 1200oC, 700oC and 1000oC, respectively, which were decomposed to beta tricalcium phosphate ( – TCP) beyond these critical temperatures. Dilatometric study of all green specimens prepared from such nanoparticles was conducted up to 1250oC to synchronize the sintering temperature. The densification behaviour was dramatically changed with respect to morphology when sintered at different temperatures; such as 700oC,900oC,1000oC, 1250oC, respectively. Scanning electron microscopic (SEM) image, apparent porosity and relative density were studied to justify the densification behaviour of HA nanoparticles.