Abstract
The research described in this thesis involves the use of surface acoustic waves to interrogate materials with property gradients, such as carburized steel, for depth of the surface treatment. A 3.5 MHz wedge transducer was used to generate Rayleigh waves which were detected with a fiber optic based interferometer. Experimental dispersion data, phase velocity as a function of frequency, was calculated from the recorded displacement-time waveforms. The phase velocity was lower in the carburized case of the material which has a greater carbon content and hardness value. Dispersion was observed by plotting phase velocity versus wavelength/residual case depth ratio. A linear fit was applied to the data with wavelength/residual case depth less than 2, and using this fit, it would be possible to non-destructively estimate case depth.
Peterman, Pamela Lane (1994). Non-destructive surface characterization of carburized steel using Rayleigh waves. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1994 -THESIS -P479.