Formation of Heterogeneous Microstructure in AA1050/AA5052/AA6061/AA1050 Layered Sheet Processed by Cold Roll-Bonding...

Area of Science:

• Materials Science
• Metallurgy
• Mechanical Engineering

Background:

• Multi-layer clad sheets offer unique material properties.
• Aluminum alloys are widely used in various industries.
• Cold roll-bonding is an effective solid-state joining technique.

Purpose of the Study:

• To fabricate a four-layer clad sheet of AA1050/AA6061/AA5052/AA1050 using cold roll-bonding.
• To investigate the microstructural evolution of the clad sheet after annealing.
• To analyze the formation of heterogeneous structures and textures.

Main Methods:

• Fabrication of a four-layer clad sheet via multi-pass cold rolling at ambient temperature.
• Annealing treatment of the clad sheet at temperatures ranging from 200 to 400 °C for 0.5 hours.
• Microstructural analysis using electron back scatter diffraction (EBSD) to study deformation and recrystallization.

Main Results:

• The as-rolled clad sheet exhibited elongated grains along the rolling direction.
• Annealing resulted in a heterogeneous microstructure containing both deformed and recrystallized structures.
• Nanometer-order grains were observed within the recrystallized regions.
• EBSD analysis revealed the detailed formation of heterogeneous structures and textures during annealing.

Conclusions:

• Cold roll-bonding followed by annealing is a viable method to produce complex multi-layer aluminum alloy structures.
• Annealing induces significant microstructural changes, leading to a mix of deformation and recrystallization.
• The resulting heterogeneous microstructure and texture are dependent on annealing temperature and time.