Microstructure Homogenization of 7075 Alloy by a Novel Electric Pulse Rheo-Rolling Process

Abstract

The microstructure and solute solid solubility of Al-7075 strips produced by a novel rheo-rolling process under an electric pulse field were investigated in detail. The pulse parameters were optimized as follows: 400 I peak current, 20 Hz operating frequency, and 10% duty factor. The primary dendrite arm was refined to a size lower than 100 µm. Moreover, the central segregation bands almost disappeared. The netlike T phases were resolved while the proportion of η and CuMg₂ phases improved. Additional atoms, especially Mg, were diffused from deposition to matrix, resulting in solute concentration in and around the precipitates.

Keywords:

• 7075
• Alloys
• Aluminum
• Electric
• Microstructure
• Pulse
• Rolling
• Segregation