Research Projects

Aluminum alloys, particularly Al-Cu alloys, are crucial structural materials systems for space and aerospace applications due to their age-hardening properties and resistance to dislocation motion. However, their use is limited at elevated temperatures due to rapid coarsening of θ' precipitates. Recently, micro-alloying of baseline Al-Cu alloys with Mn and Zr improved high temperature yield strength, creep, and fatigue properties. Al-Cu-Mn-Zr (ACMZ) alloys show excellent stability for metastable θ' precipitates up to around 400⁰C due to solute segregation at mobile interfaces. The ACMZ alloy was developed primarily for automobile applications and is currently used exclusively in that form. However, a wider application of this alloy requires complex shaping through thermomechanical processing routes. Limited information exists on the high temperature deformation behavior of ACMZ alloys, and no attempt has been made to develop the wrought version of these cast "superalloys" or study the micro- and nano-structure plus texture evolution upon thermomechanical processing (TMP). The proposed work plan aims to optimize TMP conditions for wrought processing, understand microstructure and bulk and micro-texture evolution after wrought processing, and evaluate the ageing kinetics in wrought alloys for optimized high temperature properties and thermal stability. This includes conducting hot compression tests over a large temperature-true strain rate matrix, developing a processing map for ACMZ alloy, conducting extensive microstructure and bulk and micro-texture characterization, understanding ageing kinetics and precipitate structure evolution, and conducting high temperature mechanical characterizations and strength modeling for wrought ACMZ alloys.