Advanced Aluminum Materials for Elevated Temperature Applications

Elevated temperature performance of advanced aluminum alloys is essential to usage in certain aircraft applications, for example in-air systems, auxiliary power units, and in or near engines.  Constellium is actively supplying materials for use in these types of environments including alloys such as 2219, 2618, and 6056. 

In addition, Constellium has characterized the elevated temperature behavior of a number of proprietary products made of advanced conventional and AIRWARE^® alloys including 2139, 2022 and 2050.  Relevant evaluation parameters included creep resistance and thermal stability. The latter is characterized by the room temperature tensile yield stress after elevated temperature exposure.  This was accomplished either by extending the aging time or performing a separate high-temperature treatment after a conventional aging practice.  The interesting property balances of these materials, including their high temperature performance, make possible their use in demanding applications.

This presentation reviews new options for improved performance of components as well as current research and development of new alloy compositions specifically designed for use at elevated temperature.  Our investigations examined the effect of variations in the amount of Cu and Mg.  These alloys have different volume fraction of S’ (Al₂CuMg) and θ’ (Al₂Cu) precipitates as a result of their compositions.  The coarsening kinetics of these precipitates influences the evolution of properties during continued high temperature exposure.  A discussion is provided concerning the effectiveness of the various approaches to improving high temperature performance.