Mechanical and thermal shock properties of size graded MgO-PSZ refractory
Journal
Journal of the European Ceramic Society
Journal Volume
20
Journal Issue
8
Pages
1159-1167
Date Issued
2000
Author(s)
Abstract
The effects of the mixture of coarse powder with fine PSZ powder on the thermal-mechanical properties of 10 Mg-PSZ samples were studied. The size graded specimens were injection-molded using 3.5 m% MgO-ZrO 2 powders. The physical properties of the ZrO 2 samples and five thermal shock parameters were measured and calculated. These properties included density (ρ), porosity (p), the ratio of m/(t+c+m) phase, fracture toughness (K(IC)), strength (σ(f)), Young's modulus (E), shear modulus (G), Poisson's ratio (v), and the thermal expansion (α) between ambient temperature to 1100°C. The toughness and thermal shock resistance of the PSZ are controlled by the states of porous microstructure which can be represented by a parameter (nominal largest tolerable length of defects) a(t). The PSZ samples show two types of thermal shock behavior differentiated by comparing the value of a(t) to the characteristic length L(f) of the defects in the sintered PSZ. The states of the defects, i.e. porosity, are the microstructural evidence to explain the relationship between the thermal shock properties. (C) 2000 Elsevier Science Ltd. All rights reserved. The effects of the mixture of coarse powder with fine PSZ powder on the thermal-mechanical properties of 10 Mg-PSZ samples were studied. The size graded specimens were injection-molded using 3.5 m% MgO-ZrO 2 powders. The physical properties of the ZrO 2 samples and five thermal shock parameters were measured and calculated. These properties included density (ρ), porosity (p), the ratio of m/(t + c + m) phase, fracture toughness (K IC), strength (σ f), Young's modulus (E), shear modulus (G), Poisson's ratio (ν), and the thermal expansion (α) between ambient temperature to 1100°C. The toughness and thermal shock resistance of the PSZ are controlled by the states of porous microstructure which can be represented by a parameter (nominal largest tolerable length of defects) a t. The PSZ samples show two types of thermal shock behavior differentiated by comparing the value of a t to the characteristic length L f of the defects in the sintered PSZ. The states of the defects, i.e. porosity, are the microstructural evidence to explain the relationship between the thermal shock properties.
Type
journal article