Elastic Moduli Measurements at Elevated Temperatures using Ultrasonic Waveguide Embodiments

A measurement method is described here using a waveguide based technique with special modifications to the end of the waveguide in order to obtain reliable reflected ultrasonic signals from the end of the waveguide that is inside a heating chamber. The interpretation of the reflected signals leading to a quantitative measurement of moduli of the waveguide material i.e. Young‟s (E) and shear (G) at different temperatures. The technique uses guided ultrasonic wave modes, that are generated using an ultrasonic transducer at one end of the wave guide, travelling along the length of the waveguide, interacts with the end of the waveguides, and is reflected back to the transducer. The end of the waveguides has a bend or a step that provides a reference reflected signal. The reflected signal are detected and recorded at different steady state temperatures. The time of flight difference (δTOF), as a function of temperature, between the guided wave reflections from the embodiment and the end of the waveguide, is used to measure the moduli. Here, the L (0, 1) wave mode is used for measuring E and T(0,1) mode for G. The comparison between the literature and the measured values were found to be in agreement.