Effect of SiC nanoparticles on manufacturing process, microstructure and hardness of Mg-SiC nanocomposites produced by mechanical milling and hot extrusion
Effect of SiC nanoparticles on manufacturing process, microstructure and hardness of Mg-SiC nanocomposites produced by mechanical milling and hot extrusion
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DOI：
10.1016/j.msea.2018.09.106
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发表时间：
2018-12-19
期刊：
影响因子：
6.4
通讯作者：
Kamrani, Sepideh
中科院分区：
文献类型：
--
作者：
Penther, Daniela;Ghasemi, Alireza;Kamrani, Sepideh
通过粉末冶金技术制备具有均匀分布的SiC纳米颗粒的完全致密的Mg-SiC纳米复合材料仍然是一个具有挑战性的问题。我们建议结合联合收割机烧结和热挤压的机械研磨复合粉末，以涵盖已知的困难，传统的加工。在这里，我们报告的SiC纳米颗粒含量的SiC-Mg纳米复合材料的压缩性，显微结构和硬度的影响，在不同的固结步骤。采用冷等静压、烧结和间接热挤压工艺进行压制和固结。近致密的Mg-SiC纳米复合材料与1和10体积%的SiC纳米粒子的纳米粒子的均匀分布，成功地生产。采用扫描电子显微镜、X射线衍射仪和透射电子显微镜对粉末及烧结和挤压Mg-SiC纳米复合材料的微观结构进行了表征。通过维氏显微硬度测试，研究了烧结和挤压后的强化效果。纳米颗粒钉扎晶界并促进动态再结晶，使得纳米颗粒Mg基质形成并即使在最终固结步骤之后也得以保留。结果进一步表明，纳米颗粒和基体之间的界面粘附性非常好，有助于纳米复合材料的高硬度。
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.