THE EFFECT OF SILVER ON THE OROWAN STRENGTHENING OF AL-MG-AG ALLOYS AFTER THERMO-MECHANICAL PROCESSING

- Strengthening process of Al-Mg-Ag alloys after thermo-mechanical processing is important for enhancing the mechanical properties of alloys that used in automotive and aerospace and applications. Understanding how silver affect mechanism of strengthening allows for the development of stronger and lighter materials, enhancing the durability and performance in demanding environments. This study investigates the influence of silver content (0.75%, 1%, and 1.5%) and thermo-mechanical processing parameters on the mechanical properties and fracture behavior of Al-Mg-Ag alloys. Through systematic experimentation, the effects of cold rolling and aging treatments at various temperatures (150°C, 180°C, and 210°C) and durations (6h, 12h, and 24h), were examined. The results demonstrated that the optimal mechanical properties were achieved with 1.5% Ag content aged at 150°C for 24 hours, yielding an ultimate tensile strength of approximately 310 MPa while maintaining reasonable ductility. The fractographic analysis showed different failure mechanisms across different processing conditions: the rolled specimens showed characteristics of the predominantly brittle fracture, while aged specimens and solution-treated showed the main features of the ductile. The advancement in mechanical properties is attributed to the effective Orowan strengthening through the finely dispersed precipitates formation, whose morphology and distribution are significantly affected by both processing parameters and silver content. These results provided valuable insights into the optimization methodologies of Al-Mg-Ag alloys for structural applications that require high strength-to-weight ratios.