Mechanical Properties and Microstructural Evolutions of High-Pressure Torsion-Processed Al7068 Alloy
- Mechanical Properties and Microstructural Evolutions of High-Pressure Torsion-Processed Al7068 Alloy
- Oh, Juhee; Son, Sujung; Kim, Hyoung Seop; Seol, Jae Bok; Sung, Hyokyung; Kim, Jung Gi
- Date Issued
- KOREAN INST METALS MATERIALS
- The combination of severe plastic deformation, deformational heat, and frictional heat generated during the high-pressure torsion process has a great effect on microstructural evolutions, including grain refinement, dynamic recrystallization and recovery. In particular, the low melting temperature metallic alloys (e.g., aluminum and magnesium) also induce nano-precipitations in the matrix during high-pressure torsion, which results in both unique microstructure and mechanical properties of the nanocrystalline metallic materials. In this study, the mechanical properties and microstructural evolution of high-pressure torsion processed aluminum 7068 alloy at room temperature were investigated. In the early deformation stage, both grain refinement and nano-precipitates were formed that increase the strength of ultrafine-grained aluminum alloy, and a maximum strength of 844 MPa was obtained for the 5T sample. However, in the later deformation stage, tensile strength decreases with the increase in shear strain due to grain growth, and coarse precipitates act as crack initiation sites during plastic deformation. In summary, the mechanical properties of highpressure torsion represent the strength-ductility trade-off as the increase of the number of revolutions. Their mechanical properties are superior to those of recent severe plastic deformation-processed aluminum alloys. This result shows that the severe plastic deformation of the HPT process positively contributes to their mechanical properties by inducing multiple strengthening paths, such as grain refinement and nano precipitation of the aluminum alloy.
- Article Type
- KOREAN JOURNAL OF METALS AND MATERIALS, vol. 61, no. 1, page. 1 - 8, 2023-01
- Files in This Item:
- There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.