High temperature thermal and mechanical stability of high-strength nanotwinned Al alloys. (15th February 2019)

• Record Type: Journal Article
• Authors: Li, Qiang; Cho, Jaehun; Xue, Sichuang; Sun, Xing; Zhang, Yifan; Shang, Zhongxia; Wang, Haiyan; Zhang, Xinghang
• Is Part Of: Acta materialia. Volume 165(2019)
• Page Start: 142
• Page End: 152
• Publication Date: 2019-02-15
• Subjects: Nanotwins -- Al alloys -- Thermal stability -- High-strength -- Nanomechanical testing; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2018.11.011
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Al alloys have widespread applications, but often suffer from low yield strength. Recently, nanotwinned Al-Fe solid solution alloys have shown high flow stress (>1.5 GPa), ascribed to nanograins with abundant incoherent twin boundaries and solute-stabilized 9R phase. However, the high temperature mechanical behaviors of high-strength twinned Al-Fe alloys remain unknown. In this study, we show that nanotwinned microstructures are stable up to 280 °C, followed by recrystallization at 300 °C. In-situ uniaxial compression tests in a scanning electron microscope show that the nanotwinned Al alloys retain their high flow stress of ∼1.3 GPa when tested up to 200 °C, and substantial softening occurs at a test temperature of 300 °C. This work reveals the superb thermal stability and high temperature mechanical behaviors of the nanotwinned Al-Fe alloys, and offers a new perspective to design future strong and thermally stable nanostructured Al alloys. Graphical abstract: Image 1