Determination of Elastic Modulus by Resonant Ultrasound Spectroscopy

Faculty Mentor – Dr. Chawla

The Department of Materials Science & Engineering has an apparatus called resonant ultrasound spectroscopy (RUS), which provides a non-destructive and relatively inexpensive method of determining a material’s elastic moduli such as Young’s modulus, shear modulus, and Poisson’s ratio. The RUS method uses the inherent resonant frequencies of a material to derive its dynamic elastic constants. The sample is placed between two piezoelectric transducers; one excites the sample over a range of frequencies while the other measures the amplitude of the sample’s response. The resonant frequency spectrum of the sample, together with its mass and dimensions, is used via iterative calculations to obtain the complete set of elastic constants for the material. REU student Sara Scarritt learned to use the RUS apparatus in 2002 and determined the elastic properties of some important phases in lead-free Ag-Sn solder system. These results are now being prepared for an REU publication.