6:15 PM - 7:30 PM
[SCG57-P11] Grain growth of nanocrystalline labradorite
In this study, sintering of labradorite polycrystalline were performed by using nanoscale powders of natural labradorite, and grain growth kinetics was studied in sintered polycrystalline labradorite. We prepared nanoscale mineral powders from natural crystals of labradorite (Ab38An62) by milling. Sintering experiments were carried out at a temperature of 1100-1210 ℃ with controlling time after milling and formed mineral powders. Starting materials were characterized by electron probe micro analysis (EPMA). The resultant materials were characterized by X-ray powder diffraction (XRD), secondary electron microscope (SEM) and Xray fluorescence (XRF) analysis.
Grain growth occurred with increasing sintering temperature or sintering time. The experimental data can be fit the following relation, Dfn-D0n = kt where n is a constant, Df and D0 are the grain size at time t = t and t = 0 respectively, and k is a rate constant. For sintering, a temperature of 1100-1210 ℃ with controlled time can provide high dense aggregates of labradorite with an average grain size of 0.5micro m, porosity of 3vol% and volume reduction of 60%. In this study, we found that high dense and fine grain polycrystalline Labradorite can be made from nano-sized powders (<100nm) by atmospheric pressure sintering.