SiC／AZ61镁基复合材料蠕变性能的研究

采用搅熔铸造法制备碳化硅颗粒增强镁基复合材料SiC／AZ61，通过动态机械热分析、显微组织观察和XRD衍射分析了其蠕变性能。结果表明：碳化硅颗粒的加入细化了晶粒，SiC大多分布在晶界处，颗粒镁基复合材料的蠕变性能与AZ61合金相比得到了显著的改善。蠕变性能的提高主要因为高温时具有高的热稳定性的SiC颗粒取代晶界处高温下易软化的8相（Mg17Al22）钉扎晶界，阻止了晶界的交滑移和位错的攀移。

Study on Creep Properties of SiC/AZ61 Composites Reinforced with SiC Particles

SiC/AZ61 composites reinforced with SiC particles was fabricated by Stirring-Melt Casting technique. The creep properties of the composites have been studied by dynamic mechanical thermal analysis, micro-structural and XRD observation. The results show that the matrix grains with SiC particles introduced were refined obviously at high temperature and creep properties of SiC/AZ61 composites were improved comparing with AZ61 alloy. It is because that SiC particles substitute Mg17 Al12 phase on grain boundaries which are easily intenerated at high temperature. The pinning of SiC particles prevents dis location and slipage of grain boundary at high temperature.