17th International Conference on Textures of Materials | |
Microstructure and texture of zinc deformed by extrusion with forward-backward rotating die (KoBo) | |
材料科学;物理学 | |
Sztwiertnia, K.^1 ; Kawalko, J.^1 ; Bieda, M.^1 ; Jaskowski, M.^2 ; Piela, K.^2 ; Bochniak, W.^2 | |
Institute of Metallurgy and Materials Science, Polish Academy of Sciences, Krakow, Poland^1 | |
Faculty of Non-Ferrous Metals, AGH - University of Science and Technology, Krakow, Poland^2 | |
关键词: Deformation path; Hall-Petch relation; High angle grain boundaries; High mechanical properties; High resolution electron backscatter diffractions; Polycrystalline; Propagation of cracks; Submicron scale; | |
Others : https://iopscience.iop.org/article/10.1088/1757-899X/82/1/012084/pdf DOI : 10.1088/1757-899X/82/1/012084 |
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学科分类:材料科学(综合) | |
来源: IOP | |
【 摘 要 】
The KoBo device is a press with a cyclically rotating die enabling extrusion of ingots with the permanent destabilization of their substructure. The method involves a cyclic change of deformation path that increases the plasticity of the material and inhibits formation and propagation of cracks. The possibility of using KoBo for obtaining zinc wires with high mechanical properties was explored. A polycrystalline zinc ingot of purity of 99.995% was subjected to extrusion at room temperature. The microstructure of the material was investigated primarily via high-resolution electron backscatter diffraction using a scanning electron microscope. The microstructure is heterogeneous and consists of grains elongated slightly in the extrusion direction (ED). The material has a relatively sharp nearly axial texture with the ED scattered between theanddirections. More than 95% of high-angle grain boundaries do not correspond to any twin or low Σ CSL boundaries. The dimensions of the grains range from 10 - 20 micrometers down to the sub-micron scale. Despite the relatively large grains, the final product exhibits very good mechanical properties, which could not be explained by the Hall - Petch relation. It was found that besides grain refinement two other effects could affect the material mechanical properties. These effects are formation of nanograins inside the large, micrometer-sized grains and formation of broad areas of high-density crystal lattice defects extended along the HAGBs.
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Microstructure and texture of zinc deformed by extrusion with forward-backward rotating die (KoBo) | 941KB | download |