Impact of Al2O3-40 wt.% TiO2 feedstock powder characteristics on the sprayability, microstructure and mechanical properties of plasma sprayed coatings

Richter, A. and Berger, L.-M. and Sohn, Y.J. and Conze, S. and Sempf, K. and Vaßen, R.

Volume: 39 Pages: 5391-5402
DOI: 10.1016/j.jeurceramsoc.2019.08.026
Published: 2019

Atmospheric plasma sprayed (APS) Al2O3-TiO2 coatings have found a wide range of industrial application due to their favorable properties, combined 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 have 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 fused and crushed feedstock powders and the respective coatings. Thereby, a direct influence of Al2TiO5 content on the deposition efficiency, the porosity, the elastic modulus, and the hardness of the coatings is revealed. The results emphasize the need for a more detailed specification of commercial Al2O3-TiO2 feedstock powders to ensure a high reliability of the coating properties. © 2019 Elsevier Ltd

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