Local Elastic Property Mapping via Automation of V(z) Curve Measurements Using Short-pulse Acoustic Microscopy

Scanning acoustic microscopy (SAM) is a high-resolution nondestructive method useful for nearsurface material elastic property quantification as well as crack size determination for surface and subsurface cracks. Scanning acoustic microscopy was developed by Quate et a1. [1, 2] and has been extensively studied by a number of researchers [3-11]. The most important contrast phenomenon in SAM is the presence of Rayleigh waves, which are leaking toward the transducer and are very sensitive to local mechanical properties of the material being evaluated [12]. The generation and propagation of the leaky Rayleigh waves are modulated by the material properties, thereby making it feasible to image even very subtle changes in the elastic properties.