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Microstructure and mechanical properties of plasma sprayed nanostructured TiO2-Al composite coatings

Domenii publicaţii > Stiinte ingineresti + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: S.Ok Chwa, D. Klein, F.L. Toma, G. Bertrand, H. Liao, C. Coddet, A. Ohmori

Editorial: Elsevier, Surface and Coating Technology., 194, p.215-224, 2005.


TiO2 and TiO2–Al composite coatings were prepared by plasma spraying using a reconstituted nanosized feedstock via a spray drying
method. Effects of various spray conditions on the microstructure, porosity, microhardness and wear resistance related to the mechanical
performance of coatings were evaluated. The coatings sprayed using relatively low plasma power were composed of two distinct
microstructures of well defined lamellar structure, similar to microstructure of conventional plasma sprayed coatings generated by fully
melted particles, and embedded nano or sub-micron particles generated by partial/non-molten particles of feedstock materials. The fraction of
partial/non-molten particles in coating layers was increased by Al additive. Such a characteristic of blended microstructure of coatings was
clearly confirmed from a bimodal distribution of microhardness described by Weibull plots. The optimized addition of Al into TiO2 increased
the spraying efficiency, and also, improved mechanical properties such as microhardness and wear resistance.

Cuvinte cheie: Plasma spraying; Nanostructure; TiO2–Al composite; Microhardness; Weibull analysis