[Back]

C.M. Koller, J. Ramm, S. Kolozsvári, J. Paulitsch, P.H. Mayrhofer:
"Role of droplets and iron on the phase formation of arc evaporated Al-Cr-oxide coatings";
Surface & Coatings Technology, Volume 276 (2015), 735 - 742.

Investigations on Al-rich (Al,Cr)2O3 cathodic arc evaporated thin films showed that the hexagonal phase fractions can be increased significantly by alloying with small amounts of Fe. Based on detailed transmission electron microscopy studies we show that the hexagonal phase fraction in (Al0.76Cr0.24)2O3 and (Al0.70Cr0.25Fe0.05)2O3 coatings correlates with the presence of small spherical Cr- and Fe-enriched macroparticles. The smaller these particles are, the more likely the crystallising regions on these particles exhibit a hexagonal α-structure. This effect is clearly more pronounced in Fe-alloyed (Al,Cr)2O3 coatings. Contrary, the crystallites on macroparticles with a flattened shape-being typically Al-rich-or on rather large macroparticles, primarily exhibit a cubic structure.

Oxides; Corundum structure; Droplets; Cathodic arc evaporation; Transmission electron microscopy

http://dx.doi.org/10.1016/j.surfcoat.2015.05.012

Project Head Paul Heinz Mayrhofer:
Christian Doppler Labors für anwendungsorientierte Schichtentwicklung