Evaluating High Temperature Modulus and Strength of Alumina Tube in Vacuum by A Modified Split Ring Method

摘要

Alumina is a typical ceramic material and possesses high strength and stiffness at both room temperature and high temperature. The split ring method had been established to evaluate the elastic modulus and bending strength of alumina tube materials at ambient temperature. However, both equations for modulus and strength became lightly inapplicable with the increased temperature. For the elastic modulus, it was lack of precise approaches and advices for deformation measurement in the heating furnace. For the bending strength, changes of sample dimensions due to thermal expansion would take an effect on the calculating results. In this work, several improvements have been taken into account to calibrate the above deviations. Results revealed that the modulus and strength regularly decreased from room temperature to 1300 °C and accorded well with other conventional testing methods. It proved the accuracy and reliability of this modified split ring method, which might be used to evaluate other ceramic tube materials at high temperature.