Elastic-property measurements on CVISiC/SiC minicomposites by acoustic microscopy

In situ elastic properties of the fiber and matrix in composites obtained v ia chemical vapor infiltration/chemical vapor deposition (CVI-CVD) have bee n determined using acoustic microscopy. An unusually high frequency was use d to attain the resolution that was required by the structure and small siz e of the constituents in these nonhomogeneous materials. A coupling liquid was prepared with acoustic properties that were chosen with consideration o f the high frequency and the material characteristics. Local measurements o n the fibers and matrix were achieved by studying the acoustic signature th at was processed on very small areas. The elastic modulus of the fibers and matrices was deduced from the velocity measurements.