Correlation between surface hardness of α-alumina samples and their spectroscopic parameters

Abstract

The aim of this paper is to correlate between surface hardness of α-alumina samples with their spectroscopic parameters. A structural analysis for the alumina samples using an X-ray diffractometer (XRD) and a Raman spectroscopy was achieved where the grain size and the phase of crystallization of the samples were determined. A morphological analysis was also done by a scanning electron microscope (SEM) showing the porosity of the less hard sample. For mechanical analysis, nano-indenter (hardness and Young modulus) and micro hardness tester were used. For plasma analysis, Laser Induced Breakdown Spectroscopy (LIBS) technique has been employed. In this study, we have confirmed the previous found correlations in which a linear evolution of the ionic to atomic line intensity ratio and electronic temperature with surface hardness was obtained. This linear behavior was also obtained with electron density and vibrational temperature of AlO radical giving the alternative to determine the hardness of an unknown α-alumina using one of these spectroscopic parameters.