Nondestructive testing of coatings using ultrasonic leaky Rayleigh waves

Conference · Sat Dec 31 00:00:00 EST 1994

OSTI ID:160532

Xu, P C; Stranart, J C.E.; Meguid, S A ^[1]

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1. Univ. of Toronto, Ontario (Canada). Engineering Mechanics and Design Lab.

In an earlier work the authors successfully applied the leaky Lamb wave (LLW) technique to the measurement of elastic wave speeds in both the substrate and coating. In the present study, the leaky Rayleigh wave (LRW) technique is used to measure elastic wave speeds of the coating. In the LRW measurement, the specimen is immersed in water and the coated side is insonified obliquely by ultrasonic waves emitted from a transducer. A second transducer receives the reflected signals in a pitch-catch position. Unlike the LLW measurement, the reflection from the bottom of the substrate is gated out and the interaction between the specular reflection and the guided wave in the coating layer is optimized. For typical plasma sprayed samples, with coating thickness 0.1 mm {minus}0.3 mm, the amplitude spectrum of the recorded signals was found to have two adjacent well developed minima in the frequency range of 3--7 MHz. A theoretical model of this feature has enabled the determination of the longitudinal and transverse wave speeds of the coating.

• OSTI ID: 160532
• Report Number(s): CONF-940684-; ISBN 0-87170-509-5; TRN: 96:006059
• Resource Relation: Conference: 1994 national thermal spray conference, Boston, MA (United States), 20-24 Jun 1994; Other Information: PBD: 1994; Related Information: Is Part Of 1994 Thermal spray industrial applications: Proceedings; Berndt, C.C.; Sampath, S. [eds.] [State Univ. of New York at Stony Brook, NY (United States). Dept. of Materials Science and Engineering]; PB: 816 p.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES
COPPER ALLOYS
PLASMA ARC SPRAYING
BULK DENSITY
ELASTICITY
ULTRASONIC TESTING
NICKEL ALLOYS
INDIUM ALLOYS
TITANIUM BASE ALLOYS
ALUMINIUM ALLOYS
VANADIUM ALLOYS
RAYLEIGH WAVES
TRANSDUCERS
WAVE PROPAGATION
MATHEMATICAL MODELS
STRESSES
INTERFACES