Location

La Jolla, CA

Start Date

1-1-1998 12:00 AM

Description

The work reported here has been motivated by the need to characterise thin ceramic coatings on metallic substrates. In addition to measuring the elastic constants of the coating, which among other things is dependent on the deposition technique, it is desirable to inspect the condition of the interface between the coating and the substrate. One deposition technique involves plasma-spraying of the ceramic onto a grit-blasted metal surface. Although the top surface of the film can be polished for ultrasonic inspection, the film/substrate interface will be very rough. The Lamb wave V(z) technique has been demonstrated to be effective for the calculation of the elastic constants of thin films on substrates. The effect of surface roughness on the Lamb wave dispersion curves must be well understood however, before this method can be applied to the problem of interest here. As such, a series of tests have been performed on glass slides that have different degrees of roughness introduced on one surface.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

17B

Chapter

Chapter 5: Engineered Materials

Section

Coatings, Films and Bond

Pages

1291-1298

DOI

10.1007/978-1-4615-5339-7_167

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Lamb Wave Imaging and V(Z) Using a Broadband System

La Jolla, CA

The work reported here has been motivated by the need to characterise thin ceramic coatings on metallic substrates. In addition to measuring the elastic constants of the coating, which among other things is dependent on the deposition technique, it is desirable to inspect the condition of the interface between the coating and the substrate. One deposition technique involves plasma-spraying of the ceramic onto a grit-blasted metal surface. Although the top surface of the film can be polished for ultrasonic inspection, the film/substrate interface will be very rough. The Lamb wave V(z) technique has been demonstrated to be effective for the calculation of the elastic constants of thin films on substrates. The effect of surface roughness on the Lamb wave dispersion curves must be well understood however, before this method can be applied to the problem of interest here. As such, a series of tests have been performed on glass slides that have different degrees of roughness introduced on one surface.