Abstract
The high temperature mechanical behaviors of SiO2-based cores for the directional solidification of turbine hollow blades were investigated. Isothermal uniaxial compression tests of ceramic core samples were conducted on a Gleeble-1500D mechanical simulator with an innovative auxiliary thermal system. The stress-strain results, macro- and microstructures of SiO2-based ceramic cores were investigated experimentally. The microstructures were characterized by the scanning electron microscope (SEM). The fracture type of the SiO2-based core samples is brittle fracture, but when the temperature exceeds 1400℃, the mechanical behavior exhibits thermo-viscoelastic and viscoplastic property. Under high-temperature (＞1400℃) and stress conditions, the strength of the ceramic core is weakened attributed to the viscous slip of SiO2, which is initially melted at a temperature of 1400℃.
