Effect of ZrB2 and ZrO2 on the erosion/corrosion behavior of glass-ceramic coating

Zirconium diboride (ZrB2) and Zirconium dioxide (ZrO2) advanced ceramics are being studied for their resistivity to corrosion at high-temperature applications. Prior to controlled crystallization, these additives were subjected to milling alongside vitrified frit and other suspending agents, with weight proportions of 2%, 6%, and 10%. The assessment of erosion/corrosion resistance was carried out in accordance with the ISO 28706 standard, employing a 5 wt% of hot sodium hydroxide (NaOH) and a 10% by vol. of hydrochloric acid (HCl) at room temperature. Extensive investigations encompassed thermal and crystallographic studies, microstructural analyses, as well as elemental analysis. Consequently, the addition of ceramics led to varying degrees of enhancement up to %25 in the corrosion resistance of the coating, while acid resistance was compromised by both ceramic additions. Despite the decomposition of ZrB2 crystals at approximately 660 °C, their disintegration within the GC structure was constrained, allowing their preservation in crystal form. Furthermore, microstructural research and mechanical testing, following the BS EN 10209 standard, revealed the fundamental processes ensuring the adherence of GC coatings to the S300EK steel substrate.