Accession Number:

ADA128048

Title:

On Fatigue Crack Growth in a Ti-4.5Al-5Mo-1.5Cr Alloy with Metastable Beta-Phase.

Descriptive Note:

Final rept.,

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Report Date:

1983-05-10

Pagination or Media Count:

15.0

Abstract:

Fatigue crack growth behavior has been examined in a Ti-4.5Al-5Mo-1.5Cr alloy, for two different levels of beta-phase metastability. The resistance to fatigue crack growth appears to be marginally enhanced with the presence of metastable beta-phase in a microstructure also containing some primary alpha-phase approx 30 pct of high aspect ratio. This enhancement appears slightly greater for beta-phase water quenched from 899 deg C, than as more slowly cooled in helium from this same solution treatment temperature, at approximately an air-cooling rate. In the case of the former, nearly full retention of solute in the beta-phase is apparent, while in the latter, significant precipitation of secondary alpha-phase is evident in thin-foil transmission electron micrographs. Author

Subject Categories:

  • Physical Chemistry
  • Properties of Metals and Alloys
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE