Hot Deformation Behavior of 7085 Aluminum Alloy Based on Constitutive Model, Processing Map, and Microstructure...

Area of Science:

• Materials Science
• Metallurgy
• Mechanical Engineering

Background:

• Understanding hot deformation behavior is crucial for optimizing metal processing.
• 7085 aluminum alloy is a high-strength material used in demanding applications.
• Characterizing deformation mechanisms informs alloy design and manufacturing.

Purpose of the Study:

• To investigate the hot deformation mechanisms of 7085 aluminum alloy.
• To develop a predictive model for flow stress under various conditions.
• To identify optimal processing parameters for 7085 aluminum alloy.

Main Methods:

• Compression tests were conducted across a temperature range of 593-743 K and strain rates of 0.001-1 s^-1.
• True stress-strain curves were analyzed to determine deformation mechanisms.
• A strain-compensated Zener-Hollomon model was constructed and validated.

Main Results:

• The dominant softening mechanism is dynamic recovery, shifting to dynamic recrystallization at higher temperatures and lower strain rates.
• The Zener-Hollomon model accurately predicted flow stress with R² = 0.992.
• Instability regions were found at high strain rates; optimal processing is 693-743 K at 0.001-0.01 s^-1.

Conclusions:

• The softening mechanism transitions from dynamic recovery to a combination with dynamic recrystallization as temperature increases and strain rate decreases.
• The developed model provides a reliable tool for predicting hot deformation behavior.
• Specific temperature and strain rate ranges are recommended for optimal hot working of 7085 aluminum alloy.