Accession Number : ADP004128

Title :   High Resolution Acoustic Microstructural Characterization of Titanium with Interstitial Contamination,

Corporate Author : GENERAL DYNAMICS GROTON CT ELECTRIC BOAT DIV

Personal Author(s) : Greenburg,A. M. ; Yuhas,D. E. ; Oracvecz,M. G.

Report Date : JUL 1984

Pagination or Media Count : 17

Abstract : This investigation deals with observations relating to the acoustic characterization of the microstructure of titanium. The main idea is to relate weld integrity, or in this particular case, the level of interstitial gas contamination contained in titanium to variations in acoustic properties. The Scanning Laser Acoustic Microscope was used to obtain both images and quantitative attenuation and velocity data. Acoustic frequencies of 100 MHz and 30 MHz were used. Two different titanium alloys were tested. These include nonwelded Ti-6211 alloys as well as welded Ti-6Al4V alloy. Results indicate that substantial variations in acoustic characteristics are observed and can be correlated with the level of interstitial gas contamination. Specifically, the average acoustic attenuation is found to increase with the level of interstitial contamination. Also, the acoustic characteristics of the sample become more nonuniform or inhomogeneous with increasing contamination level. This is evidenced by large variations in the local attenuation properties (on scale of a few hundred microns). Associated with the inhomogeneous attenuation characteristics are large, discontinuous sonic velocity variations. (Author)

Descriptors :   *Titanium alloys, *Microstructure, *High resolution, *Interstitial, *Contamination, *Acoustic properties, Acoustic microscopes, Acoustic attenuation, Acoustic velocity, High frequency, Acoustic images, Scanning, Laser beams, Detectors, Oxygen, Cracks

Distribution Statement : APPROVED FOR PUBLIC RELEASE