Development of Scanning Amplitude-and-Phase Acoustic Measuring Microscope System for Measurement of Distribution of Elastic Moduli

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The purpose of the present research is the development of scanning amplitude-and-phase measuring acoustic microscope system to measure distribution of elastic moduli in local area on material surface.At first, the properties of acoustic lenses was considered to apply the amplitude-and-phase measuring acoustic microscope to analysis of complex V(z) curve from numerical simulation. It is obtained that the good lens has large and stable amplitude to normalized wave number on its transfer function. By the lens, the signals of longitudinal and transverse waves are determined on the reflectance function clearly and the precision for wave velocity of Rayleigh's wave is improved.In the system, we tried to develop the software to control the scanning table efficiently. When elastic moduli are measured at local circular area with 10mm diameter, the precision of the measurement is less than 0.2% at local area under 1mm^2. As one of the important applications of engineering, the mechanical properties of single crystal material and thin-film/substrate structures were measured. The anisotropy of single crystal GaAs (001) were determined by the system expanded to line focus acoustic lens. The Gold film on glass were used as the specimen of the film/substrate structure. The velocities of Rayleigh's and Sezawa's waves could be estimated, since the longitudinal and transverse wave are too weak in thin film. Then, the dispersion curve of surface wave is efficient to identify elastic moduli, density and thickness of the film.