Tribological Properties of Plasma Sprayed Alumina, Alumina-Titania and Alumina-Zirconia Coatings
L. Marcinauskasa, b, M. Milieškab, J.S. Mathewa, V. Dovydaitisa, R. Kėželisb, S. Tučkutėc
aDepartment of Physics, Kaunas University of Technology, Studentų Str. 50, LT- 51368 Kaunas, Lithuania
bPlasma Processing Laboratory, Lithuanian Energy Institute, Breslaujos Str. 3, LT-44403 Kaunas, Lithuania
cCenter for Hydrogen Energy Technologies, Lithuanian Energy Institute, Breslaujos Str. 3, LT-44403 Kaunas, Lithuania
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Alumina, alumina-titania and alumina-zirconia coatings were formed on stainless steel (AISI 304L) via atmospheric plasma spraying. The surface morphology, elemental composition and phase structure of the as-sprayed coatings were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The influence of feedstock powder nature on the tribological properties of the coatings were measured under dry-sliding conditions. The energy dispersive X-ray spectroscopy measurements indicated that the amount of zirconium and titanium on the surface of the coatings was 0.76 wt.% and 3.9 wt.%, respectively. The friction coefficient and wear rate of the steel substrate was 0.75 and 1.29×10-4 mm3/(N m), respectively. It was demonstrated that the addition of titania or zirconia enhanced the friction coefficient of the composite alumina coatings up to 0.63 and 0.65, which was ~12% and ~16% higher when compared to alumina coating. In addition to the increase of the friction coefficient values, all as-sprayed coatings demonstrated superior wear resistance when compared to the steel substrate.

topics: plasma spraying, alumina-zirconia, alumina-titania coatings, tribological properties