Temperature-strain rate-dependent flow stress model of ceramic materials

Abstract

Flow stress is one of the most significant plastic mechanical properties of ceramic material at high temperature, and it is crucial to its processing and manufacturing. In the present paper, a novel temperature-dependent flow stress model for ceramic materials is proposed firstly. The model establishes a clear and meaningful relationship between the flow stress and various material parameters including temperature, elastic modulus, Poisson’s ratio, melting point, and particularly, without any fitting parameters. Then, the individual effect of strain rate and the coupling effect of temperature and strain rate on flow stress is investigated. In this way, a new temperature-strain rate-dependent flow stress model for ceramic material is developed. And the model is verified by comparison between its predicted data and the available experimental results of different ceramic materials. So that the variation law of flow stress with temperature and strain rate can be well described by the presented model. In addition, compared with traditional models, the presented model has simpler form, clearer mechanism and fewer fitting parameters. Achievements of this paper can provide a foundation for the service stability and safety evaluation of ceramic materials.