The Determination of Tensile Stresses Using the Temperature Dependence of Ultrasonic Velocity

The effects of applied tensile stresses on the temperature dependence of 10 MHz ultrasonic longitudinal velocity have been studied in three types of commercial aluminum alloys, 6064-T4, 2024-T351, and 3003-T251. In all measurements, it is found that the velocity decreases linearly with temperature, and the slope of the linear relationshi\u27p changes considerably as a function of applied tensile stresses within the elastic limit of the specimen used. Furthermore, the results indicate that the relative changes in the temperature dependence of the velocity due to stress is insensitive to composition and texture, and the data obtained on the different types of aluminum alloys can be represented by a single relationship. The sensitivity of the temperature dependence of the ultrasonic velocity to applied elastic stress is estimated to be ±8 MN/m2 which compares favorably with those obtained by other techniques