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2019
Journal Article
Titel
Impact of Al2O3-40 wt.% TiO2 Feedstock Powder Characteristics on the Sprayability, Microstructure and Mechanical Properties of Plasma Sprayed Coatings
Abstract
Atmospheric plasma sprayed (APS) Al2O3 TiO2 coatings have found a wide range of industrial application due to their favorable properties in combination with low costs and a high availability. However, the detailed effect of the phase composition and the element distribution of the feedstock powders on the coating properties and the spraying process has only crudely been investigated so far. Here the impact of aluminum titanate (Al2TiO5) on the microstructural features and mechanical properties of Al2O3 40 wt.% TiO2 APS coatings is demonstrated by investigating the detailed phase composition and the distribution of aluminum and titanium in three different fused and crushed feedstock powders and the respective coatings. Thereby, a direct influence of the Al2TiO5 on the deposition efficiency, the porosity, the elastic modulus, and the hardness of the coatings is revealed. In particular, the feedstock powder had a stronger effect on the coating properties than increasing the stand off distance from 150 to 350 mm. Furthermore, Al2TiO5 coatings were found to exhibit a strong texture. The obtained results emphasize the need for a more detailed specification of commercial Al2O3 TiO2 feedstock powders in terms of their phase composition and elemental homogeneity to ensure a high reliability of the coating process and ultimately the coating properties.
Author(s)