Location

Snowmass Village, CO

Start Date

1-1-1995 12:00 AM

Description

Ultrasonic techniques are being currently used in a wide range of applications. However, there are situations where it is difficult to utilize ultrasound for NDT purposes. They are severely limited in non-contact applications due to attenuation in air. Since the present day technology requires a physical contact or a couplant between the transducer and the specimen surface to minimize diffraction effects, the temperatures sensitive piezoelectric transducers are not suited for hostile operating environments and extreme temperature gradients. Another drawback of piezoelectric transducers is the narrow banded source signals. Generation of very high frequency ultrasound becomes difficult and expensive. Complex contoured specimens are, also, difficult to handle, since traditional ultrasound is sensitive to the normalization of the incident ultrasonic beam. As with all mechanical devices, the rate of scanning of these transducers is very slow.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

14A

Chapter

Chapter 2: Emerging Inspection Technologies

Section

Laser Based Ultrasonics

Pages

569-576

DOI

10.1007/978-1-4615-1987-4_69

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Effect of Surface Coatings on Generation of Laser Based Ultrasound

Snowmass Village, CO

Ultrasonic techniques are being currently used in a wide range of applications. However, there are situations where it is difficult to utilize ultrasound for NDT purposes. They are severely limited in non-contact applications due to attenuation in air. Since the present day technology requires a physical contact or a couplant between the transducer and the specimen surface to minimize diffraction effects, the temperatures sensitive piezoelectric transducers are not suited for hostile operating environments and extreme temperature gradients. Another drawback of piezoelectric transducers is the narrow banded source signals. Generation of very high frequency ultrasound becomes difficult and expensive. Complex contoured specimens are, also, difficult to handle, since traditional ultrasound is sensitive to the normalization of the incident ultrasonic beam. As with all mechanical devices, the rate of scanning of these transducers is very slow.