| Autor: |
K.B. Nie, Z.H. Zhu, K.K. Deng, J.G. Han |
| Jazyk: |
angličtina |
| Rok vydání: |
2020 |
| Předmět: |
|
| Zdroj: |
Journal of Magnesium and Alloys, Vol 8, Iss 3, Pp 676-691 (2020) |
| Druh dokumentu: |
article |
| ISSN: |
2213-9567 |
| DOI: |
10.1016/j.jma.2020.04.006 |
| Popis: |
Mechanical properties of microalloying Mg–2.2Zn–1.8Ca–0.5Mn (wt%) matrix composites reinforced by 0.5 wt% TiC nanoparticles before and after extrusion were investigated based on the detailed microstructural analysis. A uniform distribution of TiC nanoparticles was realized in the nanocomposite by the method of ultrasonic-assisted semisolid stirring. The morphology of eutectic Ca2Mg6Zn3 phases changed from plate-like in the free TiC nanoparticles region to lamellar in the dense TiC nanoparticles region for the as-cast nanocomposite. Both the grain structure and precipitates were obviously refined as the extrusion temperature decreased from 350 to 270 °C. The nanocomposite exhibited excellent tensile yield strength (352–428 MPa) which was governed by the extrusion temperature. The grain refinement strengthening with the contribution ratio of ∼80% to this strength increment was much higher relative to thermal expansion effect, Orowan strengthening and dislocation strengthening. Ultrafine recrystallized grain structure with a substantial of fine precipitates appeared in the nanocomposite extruded at 270 °C. The refined grain structure was not only due to dynamic recrystallization, but also the synergistic pinning effect of nano-TiCp, precipitated MgZn2 and α-Mn particles. The tensile toughness value of nanocomposite after extrusion improved with increasing the extrusion temperature. Massive micro-cracks formed along the remnant coarse Ca2Mg6Zn3 led to the structural failure during tension. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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