Determination of elastic constants of Inconel-۶۲۵ superalloy, using laser-based ultrasonic

AbstractThis paper deals with the determination of the elastic constants of Inconel-۶۲۵ from the analysis of laser-generated ultrasonic bulk waves. A pulsed Nd/YAG laser (۱۰۶۴ nm) is used for ultrasonic generation in a thick stepped Inconel-۶۲۵ sample, and a He–Ne laser is used for heterodyne detection of the laser-generated signals. Ultrasonic signals obtained at epicenter and at off-epicenter position of the detection points are analyzed using wavelet transforms. Here, the identification of pressure as well as shear waves and the estimation of their velocities are done successfully. From the estimated velocities, the elastic constants (Young’s modulus, shear modulus, bulk modulus, Lames constant and Poisson’s ratio) are calculated. The agreement of these constants with the standard values confirms the identification of shear waves at off-epicenter position. The work presented in this paper brings out the applicability of the study of laser-generated bulk waves for the determination of elastic constants of any bulk material.

Keywords:

Laser , based ultrasonics (LBU) , Wavelet Transforms , Pressure waves , Shear waves , Elastic constants , Inconel