Creep degradation characterization of titanium alloy using nonlinear ultrasonic technique

A through transmission nonlinear ultrasonic measurement has been proposed to characterize the creep degradation of titanium alloy that was conducted by creep tests at temperature of 600 degrees C. The experimental results show a change of "N"-like shape of the acoustic nonlinearity versus the creep loading time, which reveal based on metallographic studies that the variation of acoustic nonlinearity is closely related to the microstructure evolutions. An analytical model calculation has revealed a good agreement with the measured result, which indicates that the precipitate-dislocation interaction is likely the dominant mechanism responsible for the change of acoustic nonlinearity in the crept materials. (C) 2015 Elsevier Ltd. All rights reserved.