Ceramics-Silikáty 58 (1) 39-45 (2014)

EVALUATION OF CORROSION OF ENGINEERING CERAMICS BY ATOMIC EMISSION SPECTROMETRY IN INDUCTIVELY COUPLED PLASMA

An analytical method has been developed and verified, facilitating chemical analysis of saline aqueous solutions from corrosion tests of two types of engineering ceramics, i.e. polycrystalline alumina, and silicon nitride. The method is capable of providing complementary information related to mechanisms of corrosion and kinetics of dissolution of the two main components of the ceramics, i.e. Al in α-Al₂O₃, and Si in Si₃N₄. A radially viewed inductively coupled plasma atomic emission spectroscopy was used, and the operating conditions for the analysis were optimised. The method was validated. Internal standardisation, matrix matching, standard addition technique and direct measurement without matrix correction were applied, and the results were critically discussed. The technique of internal standard was shown to be the most sensitive. The method exhibited satisfactory precision (relative standard deviation up to 5 %), analytical recoveries from 95 to 100 %, and acceptable limits of detection based on 3σ criterion of 0.095 mg∙l^-1 for Al (measured at 308.215 nm) and 0.099 mg∙l^-1 for Si (at 251.611 nm).

Keywords: ICP OES, Matrix effect, Ceramics, Corrosion, Alumina, Silicon nitride