PSI - Issue 21

Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 21 (2019) 73–82

© 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/ Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers Abstract Mg and its alloys have r c ntly been becoming attractive mater als for structur applications since they possess low density a d high specific strength. Severe plastic eformation (SPD) has been used to improve further thes advantage of AZ31 alloys. Wrought AZ31 alloys were first subjected to a new twist extrusion technique called nonlinear twi t extrusion (NTE) at different conditions. Deformation was ach eved at a low temperature of as ow a 373 K w thout fractures on pecimen at relatively moderate strain rates. This s du to the die geometry of NTE which is actically design d t impose plastic strain more effectively and u iformly by minimizing rigid body rotation, loc lized st ain and inhibit strain reversal which tards d slocation ac umulation a d grain refin ment. These aims to overcome the limitati s of the convention twis extru ion (TE). The microstructure d mechanical properties were exa ined before and after NTE. The mechanical propertie were invest gated by Vickers’s hardness test and tens le test. A survey of the entire literature on SPD of AZ31 reveals that highest hardening is achieved by grain refinement and dislocation accumulation after 1 pass NTE with improved homogenous structure, which results in improved mec anical prop rties. © 2019 The Autho s. Publ shed by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/ Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers Abstract Mg and its alloys have recently been becoming attractive materials for structural applications since they possess low density and high specific strength. Severe plastic deformation (SPD) has been used to improve further these advantage of AZ31 alloys. Wrought AZ31 alloys were first subjected to a new twist extrusion technique called nonlinear twist extrusion (NTE) at different conditions. Deformation was achieved at a low temperature of as low as 373 K without fractures on specimen at relatively moderate strain rates. This is due to the die geometry of NTE which is tactically designed to impose plastic strain more effectively and uniformly by minimizing rigid body rotation, localized strain and inhibit strain reversal which retards dislocation accumulation and grain refinement. These aims to overcome the limitations of the conventional twist extrusion (TE). The microstructure and mechanical properties were examined before and after NTE. The mechanical properties were investigated by Vickers’s hardness test and tensile test. A survey of the entire literature on SPD of AZ31 reveals that highest hardening is achieved by grain refinement and dislocation accumulation after 1 pass NTE with improved homogenous structure, which results in improved mechanical properties. Keywords: twist extrusion;severe plastic deformation;magnesium alloys;microstructure;mechanical properties 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials Improvement of the Mechanical Properties of Magnesium Alloy 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials Improvement of the Mechanic l Properties of Magnesium Alloy AZ31 Using Non-linear Twist Extrusion (NTE) Nathaniel Mupe a* , Hiroyuki Miyamoto a , Motohiro Yuasa a a Department of Mechanical Engineering, Doshisha University, 1-3 Kyotanabe, Kyoto 610-0394, Japan AZ31 Using Non-linear Twist Extrusion (NTE) Nathaniel Mupe a* , Hiroyuki Miyamoto a , Motohiro Yuasa a a Department of Mechanical Engineering, Doshisha University, 1-3 Kyotanabe, Kyoto 610-0394, Japan

Keywords: twist extrusion;severe plastic deformation;magnesium alloys;microstructure;mechanical properties

* Corresponding author. Tel.: +81-774-65-6406; fax: +81-774-65-6406. E-mail address: ctwc2503@mail4.doshisha.ac.jp * Corresponding author. Tel.: +81-774-65-6406; fax: +81-774-65-6406. E-mail address: ctwc2503@mail4.doshisha.ac.jp

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/ Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers 2452 3216 © 2019 Th Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/ Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers 10.1016/j.prostr.2019.12.088