Acoustic microscopy of heterogeneous matrix composites

It is shown that the extremely high contrast in acoustic microscopy for heterogeneous phase composites provided by modulus and density differences of the individual phase components have definite advantages over conventional microscopic techniques. However, sub-surface capabilities could be hampered by rapidly decreasing resolution due to Rayleigh wave interference. Additionally, decreasing contrast was observed as penetration increased. Detection of cracks, voids, and crazes in fiber composites by using acoustic microscopy remains a potential application if the Rayleigh wave interference can be properly accounted for in the imaging process.