Free volume formation and the high strength of pure Mg after room temperature core-sheath ECAP passes

Journal of Materials Research and Technology

Hyoung Seop Kim¹  Peyman Asghari-Rad¹  Maryam Mohri²  Mahmoud Nili-ahmadabadi³  Ali Heydarinia³ 

[1] Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, South Korea;Faculty of Materials and Metallurgical Engineering, Semnan University, Semnan, Iran;School of Metallurgy and Materials, College of Engineering, University of Tehran, Tehran, Iran;

关键词: Magnesium;    ECAP process;    Core-sheath method;    Recrystallization;    Free volume;   

DOI  :  

来源: DOAJ

【 摘 要 】

The present investigation is conducted to successfully deform pure Mg by equal-channel angular pressing (ECAP: channel angle 90°, corner angle 20°) using core-sheath configuration at room temperature. The microstructure of the sample after 4 passes of ECAP contained an average grain size of ∼0.3 μm and an excess free volume of ∼0.63% due to the formation of defects and dislocations during the ECAP process. The results show that local temperature increases up to 200 °C during the ECAP process causes dynamic recovery and recrystallization in the microstructure during deformation. The texture analysis shows that the first pass activates the non-basal sliding systems and the 4 passes present a relatively strong (0002) fiber texture. The highest ever reported tensile toughness of SPD processed pure Mg of about 1.784 GPa% with remarkable mechanical properties were achieved after 4 passes with an ultimate tensile strength of 223 MPa, yield stress of 170 MPa, and an elongation to failure of 8%.

【 授权许可】

Unknown