Effect of TiO<sub>2</sub> on mechanical and thermal properties of Al<sub>2</sub>O<sub>3</sub>-based coating via atmospheric plasma spraying
Hansol Kwon, Yeon Woo Yoo, Youngjin Park, Uk Hee Nam, Eungsun Byon
Abstract
In this study, Al2O3-based coatings with varying TiO2 contents (0, 3, 13, and 40%) were fabricated using atmospheric plasma spraying technique. To compare the superiority of the samples, their mechanical (Vickers hardness and adhesion strength) and thermal properties (thermal conductivity and thermal shock resistance) were characterized. As observed, Al2O3-40%TiO2 (A-40T) coating exhibited relatively inferior mechanical properties but superior thermal insulation and thermal shock resistance at 600°C. According to the microstructure and phase analysis, this finding is attributed to the special phase, Al2TiO5, and preexisting microcracks inside the coating. Thus, A-40T manifested excellent characteristics for thermal insulation application compared with pure Al2O3 and low-TiO2 content coatings.