Optimizing the Heat Treatment of a Novel 2xxx Aluminum Alloy

In response to the growing demand for advanced materials capable of withstanding elevated temperatures for a prolonged period of time while maintaining superior mechanical properties, this thesis investigates the strengthening and hardening potential of novel 2xxx-series Al-Cu-Mg-Ag alloys, focusing on three variants with minor additions of Zr, Ni, and Fe, and differing Mg content. This study aims to optimize both the solid solution heat treatment and the artificial aging process to enhance the alloy's mechanical properties. The respective alloys were extensively studied using a range of experimental techniques to achieve two primary objectives: (i) refining the solution heat treatment to realize an optimized supersaturated solid solution, and (ii) determining the optimal parameters (temperature and holding time) for artificial aging, including both one-step and multi-step heat treatment strategies. The effectiveness of solution heat treatments, conducted at four different temperatures for various holding times, was evaluated through scanning electron microscopy, energy-dispersive X-ray spectroscopy, and hardness testing. Natural aging after the procedure further gave indication of the highest hardening potential for the respective alloy. Artificial aging in one-step was performed at five different temperatures for up to 48 h. The investigated multi-step artificial aging process consists of two-steps a primary step at a lower temperature and subsequent step at elevated temperature. Additionally, differing solution heat treatment temperatures with subsequent one-step artificial aging were compared. After T6 heat treatments, high temperature experiments were conducted at three different temperatures for a duration of 72 h to assess the respective heat treatment potential. This comprehensive approach enabled a detailed discussion of the interplay between solution treatment conditions, aging strategies, and the resulting mechanical properties dependent on Mg content, contributing valuable insights into the optimization of the 2xxx-series Al-Cu-Mg-Ag alloys for high-performance applications.