科研之友
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摘要
Y2O3 materials have been widely applicated in high temperature industry owing to its high temperature stability. However, the poor sintering behavior and thermal shock resistance limited its application. The existing studies were focused on its sintering properties, yet the increase in densification of Y2O3 materials could weaken its thermal shock resistance. Y2O3 materials with smaller closed pores were fabricated by the decomposition of Al(OH)(3) and the effect of Al(OH)(3) on the microstructure, mechanical properties and thermal properties of Y2O3 materials were investigated in this paper. We concluded that the migration of grain boundaries was accelerated due to the ionic radii difference and the diffusion coefficient between Y3+ and Al3+, and the diffusion coefficient of Y3+ was relatively weak while the diffusion of Al3+ was mainly dominated. The Al2O3 produced by decomposition of Al(OH)(3) was active, which promoted the sintering of Y2O3 materials. Meanwhile, the porosity and pore structure of Y2O3 materials were affected by the decomposition of Al(OH)(3), and the appropriate pores improved the thermal shock resistance by absorbing thermal stresses. Furthermore, it indicated that adding Al(OH)(3) into Y2O3 materials had a powerful influence in balancing its sintering properties and thermal shock resistance. The sample with 3 wt% Al(OH)(3) exhibited the better performance in this study, with the relative density of 93.2% and the thermal shock stability factor parameter R-st of 1.74 W m(1/2).
