Optimization of spray pyrolysis zirconia coatings on aluminized steel

An exhaustive study of spray conditions is presented for ZrO2 thin films on hot-dip aluminized steel to be used as protective coatings against degradation. A fractional factorial design (2IV4-1) has been applied to reduce the number of experiments and find out main and secondary effects of spray pyrolysis variables on growth rate. Factors, as substrate temperature, solution concentration, air pressure and precursor flow rate have been studied at two levels. Results from this work will be discussed by X-ray photoelectron and UV–VIS–NIR spectroscopy and by scanning electron microscopy, finding great changes in substrate coverage, as well as optical and morphological properties for the analysed layers. A statistically significant influence of substrate temperature and precursor flow rate has been found for film growth. The co-optimization of both variables has conducted to a considerable reduction of deposition time, as industrial applications and process improvements require, being that the first step for a later up-scaling of these barrier coatings.