Original paper
Plasma-sprayed 2:1-mullite coatings deposited on aluminium substrates
Heimann, Robert B.; Pentinghaus, Horst J.; Wirth, Richard
European Journal of Mineralogy Volume 19 Number 2 (2007), p. 281 - 291
published: Apr 26, 2007
Abstract
2:1-mullite coatings of (17-23) ± 6 μm thickness were deposited by atmospheric plasma spraying (APS) onto flat aluminium coupons. Scanning transmission electron microscopy (STEM) showed that the coatings immediately adjacent to the substrate interface consisted predominately of an aluminium silicate glass with varying Al/Si ratios. Residual compressive coating stresses with in-plane levels ranging from 100 to 300 MPa were determined by Cr3+ photoluminescence piezospectroscopy. The aluminium silicate glass was characterised by wide-angle x-ray scattering (WAXS) using synchrotron radiation to determine the composition (62-63 mole% Al2O3) as well as the amount of glass in the coatings (32 ± 2%).
Keywords
mullite • plasma-sprayed coatings • residual stress • aluminium silicate glass • photoluminescence piezospectroscopy • wide-angle x-ray scattering