Effect of SiC nanoparticles on manufacturing process, microstructure and hardness of Mg-SiC nanocomposites produced by mechanical milling and hot extrusion
| Autor: | Sepideh Kamrani, Claudia Fleck, Alireza Ghasemi, Daniela Penther, Ralf Riedel |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Nanocomposite Mechanical Engineering Nanoparticle Sintering 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 01 natural sciences Indentation hardness Mechanics of Materials Powder metallurgy 0103 physical sciences General Materials Science Extrusion Grain boundary Composite material 0210 nano-technology |
| Zdroj: | Materials Science and Engineering: A. 738:264-272 |
| ISSN: | 0921-5093 |
| Popis: | The production of fully dense Mg-SiC nanocomposites with a homogeneous distribution of SiC nanoparticles through powder metallurgy techniques is still a challenging issue. We propose to combine sintering and hot extrusion of mechanically milled composite powders to encompass the known difficulties of conventional processing. Here, we report on the effect of SiC nanoparticle content on the compressibility, microstructure and hardness of SiC-Mg nanocomposites during the different consolidation steps. Cold-isostatic pressing, sintering and indirect hot extrusion were used for compaction and consolidation. Near dense Mg-SiC nanocomposites with 1 and 10 vol% SiC nanoparticles were successfully produced with a homogeneous distribution of the nanoparticles. Scanning electron microscopy, X-ray diffraction and transmission electron microscopy were used to characterise the microstructure of the powders and of the sintered and extruded Mg-SiC nanocomposites. Vickers microhardness tests were done to reveal the hardening effect after sintering and extrusion. The nanoparticles pin the grain boundaries and foster dynamic recrystallisation, so that a nanograined Mg matrix develops and is preserved even after the final consolidation step. The results further show a very good interface adherence between nanoparticles and matrix contributing to the high hardness of the nanocomposites. |
| Databáze: | OpenAIRE |
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