Location

Snowmass Village, CO

Start Date

1-1-1995 12:00 AM

Description

Up to the present time, the detection of hard alpha inclusions in commercial titanium products or in billets has relied on the presence of associated voids and cracks, which due to their sharp edges are good acoustic reflectors at high frequencies. The detection problem becomes much harder, if cracks and voids are absent, since the acoustic impedance of a hard alpha inclusion is at least an order of magnitude smaller. The problem appears to call for the use of high frequency focused probes. However, one cannot use arbitrarily high frequencies for at least three reasons: (1) grain scattering due to the microstructure of titanium, (2) attenuation of the beam due to surface roughness and most importantly (3) the nature of the flaw as discussed below.

Volume

14B

Chapter

Chapter 6: Material Properties

Section

Surface Roughness

Pages

1837-1844

DOI

10.1007/978-1-4615-1987-4_235

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Ultrasonic Signals from "Worst-Case" Hard-Alpha Inclusions Beneath a Random Rough Surface

Snowmass Village, CO

Up to the present time, the detection of hard alpha inclusions in commercial titanium products or in billets has relied on the presence of associated voids and cracks, which due to their sharp edges are good acoustic reflectors at high frequencies. The detection problem becomes much harder, if cracks and voids are absent, since the acoustic impedance of a hard alpha inclusion is at least an order of magnitude smaller. The problem appears to call for the use of high frequency focused probes. However, one cannot use arbitrarily high frequencies for at least three reasons: (1) grain scattering due to the microstructure of titanium, (2) attenuation of the beam due to surface roughness and most importantly (3) the nature of the flaw as discussed below.