The theoretical calculation and experimental measurement of sapphire elastic modulus at high temperature
Sapphire is an ideal structural material for fiber-optic high temperature pressure sensors because of its good light transmittance and high temperature stability. The variation of elastic modulus of sapphire at high temperature is closely related to the accuracy of its high temperature pressure measurement. As a result, it is necessary to obtain the high temperature elastic modulus of sapphire for designing and preparing high temperature pressure sensors. Based on the in-situ XRD test at high temperature, the cell parameters of sapphire were obtained at different temperatures. The elastic properties of sapphire were then theoretically calculated by first principles, and the elastic stiffness matrix and elastic flexibility matrix of sapphire were obtained at high temperature. Meanwhile, based on the impulse excitation technique, the elastic modulus of sapphire samples were measured with different orientations from room temperature up to 1200 ℃, which verified the accuracy of theoretical calculation results. The theoretical and experimental results show that the elastic modulus of sapphire decreases at higher temperature and shows significant differences between different crystal orientations. The obtained high temperature elastic modulus data of sapphire can provide basic data reference for the design of related high temperature pressure sensors.
sapphirehigh temperature in situ XRDelastic modulusfirst principleimpulse excitation technique
万方数据
维普
