Cohesive Zone Model for Intergranular Slow Crack Growth in Zirconia and Ceramic:Influence of the water concentration and Microstructure

摘要

We describe intergranular slow crack growth (SCG) in Zirconia within a cohesive zone methodology.Stress corrosion being thermally activated,a rate and temperature dependent cohesive zone formulation is proposed and shown able to capture SCG.In the present study,the influence of microstructure in terms of anisotropic properties,the grain to grain disorientation,and the initial thermal stress state that originates from the ceramic processing are shown to determine the kinetics of SCG and the level of the load threshold below which no slow crack growth is observed.The influence of the water concentration (R.H.) on the magnitude of the minimum load threshold and on the kinetics of SCG is investigated.Ultimately,this work aims at providing reliable predictions in long lasting applications of ceramics.