Enhanced high temperature properties of ZTA prestressed ceramics reinforced by cordierite coating

Abstract

AbstractZirconia toughened alumina (ZTA) has a wide range of applications in high temperature. Though some routes were reported to enhance the mechanical properties at room temperature, the preparation of ZTA with improved high temperature properties was still unknown. In this work, cordierite/ZTA pre‐stressed ceramics (marked as Cor‐ZTA30) have been fabricated successfully by using prestressed coating reinforcement method. The relationships among the temperature, residual stress and the flexural strength of Cor‐ZTA30 have been established based on experimental data. Due to the compressive stresses exists in the surface layer of Cor‐ZTA30 hinder the crack extension, the flexural strength of Cor‐ZTA30 was greatly enhanced at the temperatures below 1000°C. In addition, the difference in flexural strength between coated and uncoated ZTA ceramics decreased with increasing temperature until 1000°C. It indicated that the residual stress vanished entirely as the temperature above 1000°C, which resulted in the same flexural strength for ZTA and Cor‐ZTA30. Therefore, strengthening ZTA ceramics by prestressing is available under the temperatures below 1000°C.