Preparation and characterization of Mg alloy rods with gradient microstructure by torsion deformation

• Published in: Metals and materials international Vol. 22; no. 5; pp. 887 - 896
• Main Authors: Song, Bo, Zhao, Huaizhi, Chai, Linjiang, Guo, Ning, Pan, Hucheng, Chen, Hongbing, Xin, Renlong
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Institute of Metals and Materials 01.09.2016; Springer Nature B.V; 대한금속·재료학회
• Subjects: Alloys; Characterization and Evaluation of Materials; Chemistry and Materials Science; Deformation; Deformation mechanisms; Dislocation density; Dislocations; Electron back scatter; Engineering Thermodynamics; Extrusion rate; Grain size; Heat and Mass Transfer; Machines; Magnesium base alloys; Magnetic Materials; Magnetism; Manufacturing; Materials Science; Mechanical properties; Metallic Materials; Microstructure; Processes; Rods; Room temperature; Shear strain; Slip; Solid Mechanics; Strain rate; Surface layers; Texture; Torsion; 재료공학; gradient microstructure; hardness; Mg alloy; torsion; texture
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-016-6226-z

Extruded AZ31 Mg alloy rods were subject to free-end torsion deformation at room temperature. The microstructure features of the torsion deformed samples were characterized using electron backscatter diffraction technique. Mg rods with gradient microstructure can be fabricated by torsion deformation. Inhomogeneous distribution of microstructure along the radial direction of the twisted rods is attributed to the linearly increasing strain accumulation and strain rate from core to surface. With increasing equivalent strain, both the amount of {10-12} twins and dislocation density increase and the c-axes of texture tend to rotate towards torsion axis. Although both dislocation slips and {10-12} twinning can be activated during torsion, dislocation slips are considered as the dominated deformation mechanism and responsible for the change of macro-texture for present torsion deformation. {10-12} twins and dislocations in the twisted samples can generate refinement hardening and dislocation hardening, respectively, to increase the hardness value.