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GEOHEX Coatings Paper Published

Mon, 27 November, 2023

A paper titled, ‘Spray Parameters and Coating Microstructure Relationship in Suspension Plasma Spray TiO2 Coatings’ has been published by MDPI open access journals.

The article was co-written by experts from the University of Leicester’s Materials Innovation Centre and TWI’s Materials Performance and Integrity Group.

Recent years have seen a growing interest in the use of thermal spray techniques using suspension or solution-based coatings. These techniques allow for the precise control of particle size and microstructure, which improve the flow of feedstock and enable high-quality coating customisation.

Spray parameters such as the stand-off distance and the feedstock flow rate can impact the performance and characteristics of coatings, which are used to help prevent corrosion, scaling and fouling in geothermal power plant heat exchangers.

Through the control of spray parameters it should be possible to help mitigate against these issues, and this paper explains how TiO2 coatings were applied to a carbon steel substrate using suspension plasma spray (SPS), enhancing the performance of geothermal heat exchanger materials.

A scanning electron microscope as well as profilometry, X-ray diffraction, and adhesion testing were used to assess the impact of stand-off distance and feedstock flow rate on the coating performance, with results showing that coatings deposited with a 10mL/min flow rate were well adhered to the substrate. However, as the stand-off distance and flow rate were increased, the poor thermal and kinetic energy between the torch and the feedstock particles led to decreased adhesion to the substrate.

You can read the paper and learn about the findings of this research in full, here.


The GEOHEX project has received funding from the European Union's Horizon 2020 research and innovation programme. Grant agreement 851917.