Strengthening effect of nano-scale precipitates in a die-cast Mg–4Al–5.6Sm–0.3Mn alloy
| Autor: | Qiang Yang, Weirong Li, Yangde Li, Fanqiang Bu, Xin Qiu, Wei Sun, Jian Meng, Xiaojuan Liu |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Materials science Mechanical Engineering Metallurgy Alloy Metals and Alloys Intermetallic 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology 01 natural sciences Precipitation hardening Mechanics of Materials 0103 physical sciences Scanning transmission electron microscopy Materials Chemistry engineering Density functional theory Dislocation Magnesium alloy 0210 nano-technology Strengthening mechanisms of materials |
| Zdroj: | Journal of Alloys and Compounds. 665:240-250 |
| ISSN: | 0925-8388 |
| Popis: | In this paper we report a quantitative study of the age-hardening in the high-pressure die-cast Mg–4Al−5.6Sm−0.3Mn alloy. The results indicate that a number of nano-scale spherical precipitates identified as Al 3 Sm using high-angle annular dark-field scanning transmission electron microscopy, precipitated in Mg matrix after aging at 150–225 °C, with no obvious changes on grain sizes, intermetallic phases formed during solidification, and dislocation densities. From the existing strengthening theory equations in which some lacking parameters were taken from the first-principles density functional theory (DFT) calculations, a quantitative insight into the strengthening mechanisms of the nano-scale precipitate was formulated. The results are in reasonable agreement with the experimental values, and the operative mechanism of precipitation strengthening was revealed as Orowan dislocation bypassing. |
| Databáze: | OpenAIRE |
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