STUDY ON THE DYNAMIC CONSTITUTIVE RELATIONSHIP AND FRACTURE MECHANISM OF FLUOROPHLOGOPITE GLASS-CERAMICS

In order to study the dynamic mechanical properties and fracture mechanism of fluorophlogopite glass-ceramics, a dynamic compression test was carried out with a high-speed hydraulic servo testing machine, and the dynamic mechanical parameters of samples at medium strain rate were obtained. The results show that the ceramic material has an obvious strain rate effect. Based on damage mechanics theory, the dynamic damage constitutive equation of elastic brittleness is obtained. The fracture mechanism is analyzed by SEM observation of the samples fracture microstructure and nano-indentation tests. The fracture macroscopic and microcosmic morphology of samples show that the material fracture mode is of brittle cleavage fracture, and there are lots of microcracks at the interface between a mica phase and glass. The nano-indentation test verifies the existence of the weak interface between two phases. The microcracks are first nucleate at the junction of two phases and extend along the weak interface, and the nucleation load is 20 mN.