Recrystallization Behavior of Cold-Rolled AA5083 Microalloyed with 0.1 wt.% Sc and 0.08 wt.% Zr

Area of Science:

• Materials Science
• Metallurgy
• Physical Chemistry

Background:

• Aluminum-magnesium-manganese (Al-Mg-Mn) alloys are widely used due to their good strength-to-weight ratio.
• Controlling microstructure and recrystallization is key to optimizing mechanical properties in cold-rolled aluminum sheets.
• Microalloying offers a potential route to enhance alloy performance, but its effects on AA5083 require detailed investigation.

Purpose of the Study:

• To investigate the impact of Sc/Zr microalloying on the mechanical properties, microstructure, and recrystallization behavior of AA5083 cold-rolled sheets.
• To determine the effect of annealing temperature on these properties in both microalloyed and base alloys.
• To elucidate the mechanisms behind enhanced recrystallization resistance in Sc/Zr-containing AA5083.

Main Methods:

• Hardness testing to evaluate mechanical properties.
• Optical microscopy and electron backscatter diffraction (EBSD) for microstructural analysis.
• Transmission electron microscopy (TEM) to identify nanoscale precipitates.
• Constitutive equations to estimate grain boundary strengthening.

Main Results:

• Microalloying with 0.1 wt.% Sc and 0.08 wt.% Zr significantly increased the alloy's strength and recrystallization resistance.
• The recrystallization temperature of the microalloyed AA5083 was elevated by 250 °C compared to the Sc-free alloy, reaching 500 °C.
• Al3(Sc,Zr) nanoparticles were identified as the primary reason for delayed recrystallization due to Zener drag.
• Grain structure evolution and grain boundary strengthening were confirmed as critical factors in strength changes during annealing.

Conclusions:

• Sc/Zr microalloying is an effective strategy to improve the strength and thermal stability of AA5083.
• The presence of Al3(Sc,Zr) nanoparticles is crucial for enhancing recrystallization resistance via Zener pinning.
• Understanding grain structure evolution and boundary strengthening is essential for designing advanced aluminum alloys.