Identification of strengthening phases in Al-Cu-Li alloy Weldalite 049The tensile properties in the peak-strength T8 temper for Weldalite 049, a family of ultrahigh-strength weldable Al-Cu-Li-based alloys with a Li content ranging from 0 to 1.9 wt percent, are investigated, and strengthening precipitates at selected Li levels are identified. Relatively small amounts of Ag and Mg were found to be extremely effective in stimulating precipitation in Weldalite 049, resulting in a homogeneous distribution of fine, platelike precipitates with a 111-type habit plane in the peak-aged, T8 temper. The yield and tensile strengths are strongly dependent on Li content, with a peak in the range of 1.1 to 1.4 wt percent Li. At above 1.4 wt percent Li, strength decreases rapidly, which is associated with delta-prime precipitation. For high-resolution TEM, the structure of T(1)-type precipitates in Weldalite 049 is similar to that of T(1) platelets in 2090.
Document ID
19910059209
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Langan, T. J. (Martin Marietta Labs. Baltimore, MD, United States)
Pickens, J. R. (Martin Marietta Laboratories Baltimore, MD, United States)
Date Acquired
August 15, 2013
Publication Date
January 1, 1989
Subject Category
Metallic Materials
Meeting Information
Meeting: International Aluminum-Lithium Conference