Electrical resistivity of YSZ-coated stainless steel electrodes. A study by response surface methodology

Ceramic-coated electrodes with minimum electrical resistivity have been prepared using AISI 304 stainless steel as a substrate for the deposition of Yttria-Stabilized Zirconia (YSZ) coatings. SEM-EDX, XPS, FT-IR, GIXRD and EIS have been used to characterize the samples. The tetragonal phase of zirconia has been successfully stabilised. A statistical design of experiments has been used to analyze the influence of withdrawal rate, sintering temperature and dopant percent on the electrical resistivity of the coatings. ANOVA analysis indicates that all factors exert a statistically significant effect on the electrical resistivity at 95% of confidence. A non-linear polynomial equation (r2 = 0.9481) has been obtained in order to correlate electrical resistivity with the analyzed factors. Withdrawal rate and sintering temperature resulted to be the most important factors influencing the electrical resistivity, R. Interactions appear between all the pairs of variables. Hence, modifying one of the variables significantly affect the other ones.