Accession Number:

ADA171624

Title:

Fundamental Studies on the Aluminum-Lithium-Beryllium Alloy System.

Descriptive Note:

Final rept. Feb 84-Aug 86,

Corporate Author:

LOCKHEED MISSILES AND SPACE CO INC PALO ALTO CA RESEARCH AND DEVELOPMENT DIV

Report Date:

1986-08-01

Pagination or Media Count:

133.0

Abstract:

Recent developments in aluminum alloys for aerospace applications have emphasized low-density alloys and in large part this emphasis has been on Al-Li based alloys. The development of fine-structed Al-Li-Be alloys remains an interesting prospect for further decreasing the density and increasing the modulus of Al. The aging behavior of rapidly solidified Al-10Be-3Li ribbon has been characterized. Several conclusions can be make from this study. The general aging characteristics of the ternary Al-Be-Li alloys are very similar to binary Al-Li alloys. Although delta prime precipitates are present in the as-spun ribbon, uniform delta prime distribution was not observed until aging temperatures of about 180C. Heat treatment of the ribbon at higher temperatures, e.g., 300 C resulted in delta prime transformation. In the Al-Be-Li ternary, the Alpha-Be particles are present in the Al-Li matrix as independent dispersoids and have little effect on the aging response of the Al-Li matrix. The size of the distribution of the Alpha-Be particles is nonumiform. Upon heat treatment at temperatures higher than 300 C, Alpha-Be particles tend to coarsen and the growth behavior of these particles follows a classical Ostwald coarsening mechanism.

Subject Categories:

  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE