Microstructure evolution and mechanical properties of as-extruded Mg-Gd-Y-Zr alloy with Zn and Nd additions
| Autor: | Chao Xu, Zijian Yu, Shigeharu Kamado, Jian Meng, Xuhu Zhang |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Mechanical Engineering Alloy Recrystallization (metallurgy) 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 01 natural sciences Precipitation hardening Mechanics of Materials 0103 physical sciences Ultimate tensile strength engineering Dynamic recrystallization General Materials Science Extrusion Texture (crystalline) Composite material 0210 nano-technology |
| Zdroj: | Materials Science and Engineering: A. 713:234-243 |
| ISSN: | 0921-5093 |
| Popis: | The microstructure evolution and mechanical properties of as-extruded Mg-11.5Gd-4.5Y-0.3Zr (wt%) alloy with Zn and Nd additions were investigated. The addition of Zn inhibits the dynamic recrystallization (DRX) due to the presence of the long-period stacking ordered (LPSO) phase. The addition of Nd promotes the precipitation of the Mg5RE (RE: rare earth) phase. The existence of the densely distributed Mg5RE phase before hot extrusion promotes the DRX in subsequent hot extrusion process and leads to grain refinement. The increase in the number of Mg5RE phase particles degrades the mechanical properties of the resultant alloy. After hot extrusion, the studied alloys exhibit a bimodal microstructure consisting of fine dynamic recrystallized (DRXed) grains of several microns and strongly textured course un-DRXed grains. The as-extruded Mg-11.5Gd-4.5Y-1.5Zn-0.3Zr alloy exhibits an excellent balance of strength and ductility (tensile yield strength of 371 ± 3.0 MPa and elongation of 7.2 ± 0.8%). The alloy strengthening is attributed to the bimodal microstructure, the Mg5RE and LPSO phases, and the basal texture. The tensile yield strength of the as-extruded Mg-11.5Gd-4.5Y-1.5Zn-0.3Zr alloy can be further increased to 425 ± 2.5 MPa by precipitation hardening with the T5 treatment. |
| Databáze: | OpenAIRE |
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