Indentation Behavior Of Zirconia Ceramics At Room Temperature

Zirconia ceramics are widely applied in engineering practice as structural or functional ceramics because of its excellent physical and chemical characteristics such as strong strength, hardness, phase transformation toughening and so on. With the emergence of small or micro-scale ceramic artifacts, the understanding of the mechanical properties of Zirconia ceramics in micro-scale provides a guidance for production and application in industry. In this paper, the mechanical behaviors of zirconia ceramics were investigated by nanoindentation and the distribution of stress and strain in the process of indentation were analyzed based on finite element simulation by using ABAQUS. The related research contents and conclusion are as follows:(1)The mechanical properties of zirconia ceramics under different strain rates and depths were obtained by nanoindentation tests using Continuous Stiffness Measurement(CSM). Results show that the slope of the entirety contact stiffness-indentation depth curve(S-h curve) decreases with the maximum indentation depth when loading strain rate is fixed. For the maximum indentation depth fixed, the development tendency of hardness, elastic modulus and elastic recovery rate is consistent, which increase with the loading strain rate.In holding stage, creep displacement and the creep strain rate show obviously loading strain rate sensitivity.(2) Finite element analysis software ABAQUS was used to simulate the nanoindentation based on the double linear constitutive relation of zirconiaceramics deduced from dimensional analysis. Results indicate that the maximum mises stress occurs in the place beneath indenter and forms a hydrostatic pressure core which extend with advancement of penetration process. Shear stress induced T-M phase transformation in the elastic-plastic zone results in irregular distribution of residual stress and local plastic deformation.