| 摘要 |
The invention relates to a method of determining the thickness of a surface layer of a part having a structure different from that of the material constituting the part beneath said layer. It consists in generating a beam of Rayleigh waves on the surface of the part at a first frequency, in measuring the wave propagation velocity, in repeating the operation several times with Rayleigh waves at different frequencies, in recording the wave propagation velocities and the corresponding wavelengths and in classifying them by increasing wavelengths. The thickness of said layer is defined by the wavelength above which a plateau in the variation of said velocity is observed.
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