Comparison of the effect of sintering on the microstructure, micro hardness and phase composition of conventional and nanostructured YSZ TBCs

Abstract This paper reports on a study that investigated the effect of sintering on the microstructure, thermal properties and phase composition of nanostructured and conventional 8YSZ thermal barrier coatings. For this purpose, conventional and nanostructured YSZ coatings were heated at 1100 °C in an atmospheric box furnace for 10, 20, 50, 100, and 150 h. Optical microscope and FE-SEM were used for microstructural studies and XRD was used for phase analysis. The percent of pores and micro hardness were used as measures of sintering. According to the findings, the percent of pores and cracks decreased because of the inter-diffusion of splats. Changes in properties, such as thermal conductivity and micro hardness, during the sintering process were less significant for nanostructured coatings than they were for the conventional ones, but phase changes were more noticeable. XRD investigation showed that picks shift for both samples were the same. The findings showed that using nanostructured coatings could be a way of reducing sintering effects.