Estimation of the elastic properties of thermal sprayed coatings by inverse analysis of velocity dispersion of surface acoustic wave

摘要

Inverse analysis of the velocity dispersion of laser excited surface acoustic wave (SAW) was used to estimate the elastic properties of three types of sprayed coatings: NiCrAlY, CrNiMoSiB, and WC-cermet. The obtained esults were compared to thoseobtained by the mechanical method of a 3-or 4point bending tests for the free-standing specimen and/or sprayed specimen. A laser SAW system, consisting of a Q-switched Nd-YAG laser and a heterodyne laser interferometer, enabled the SAW to be monitored ata high spatial resolution. From the group velocity dispersion obtained by wavelet transform. the elastic properties of the sprayed coatings were estimated by simplex-assisted inverse processing. The elastic moduli determined using these methods were found to be in fairly good agreement, and thus the inverse analysis of SAW was proven to be useful for evaluating the elastic properties of sprayed coatings.