Influence of cooling rate after homogenization on the flow behavior of aluminum alloy 7050 under hot compression

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 527; no. 4-5; pp. 1200 - 1205
• Main Authors: Liu, Shengdan, You, Jianghai, Zhang, Xinming, Deng, Yunlai, Yuan, Yubao
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.02.2010; Elsevier
• Subjects: Aluminum alloy 7050; Applied sciences; Dynamic precipitation; Elasticity. Plasticity; Exact sciences and technology; Flow softening; Hot deformation; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Hot deformation; Dynamic precipitation; Flow softening; Aluminum alloy 7050; Homogenizing heat treatment; Aluminium base alloys; Plastic flow; Strain softening; Water quenching; Cooling rate; Compression test; Precipitation; Microstructure; Activation energy; Strain hardening; Flow stress; Strain rate
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2009.10.055

The influence of cooling rate after homogenization on the flow behavior of aluminum alloy 7050 was investigated by hot compression testing over a range of temperatures, 300–450°C, with strain rates of 0.001–1s−1. It was found that water-quenched alloy exhibited higher flow stresses than furnace-cooled alloy, and the difference in the peak stress decreased with temperature increasing. The strain-hardening rate during the initial stage of hot deformation was higher for water-quenched alloy than furnace-cooled alloy. During deformation at low temperatures with the lowest strain rate, flow softening was observed for both alloys, but this effect was more significant for the water-quenched alloy. The activation energy of the water-quenched alloy was more than twice higher than that of the furnace-cooled alloy. With strain increasing, the activation energy decreased for both alloys. These phenomena were explained based on dynamic precipitation and coarsening during hot deformation according to microstructure examination.