高体积分数MWCNTs/AZ80复合材料的显微组织

摘要

采用搅拌摩擦加工技术制备体积分数为19.5%的多壁碳纳米管(MWCNTs)增强AZ80镁基复合材料，研究经多道次搅拌摩擦加工(FSP)加工后复合材料的显微组织和MWCNTs在基体中的分布和稳定性，分析MWCNTs与基体的界面结构特征。结果表明：多道次FSP能提高MWCNTs在基体中的分散性，并在基体中形成了纳米晶，晶体尺寸仅5 nm左右。经多道次FSP后，MWCNTs在径向上的多壁结构未受到机械损伤，但经7道次加工后，在复合材料中发现有少量Al4C3相；碳纳米管与镁基体以半共格的界面形式相接。%The multi-walled carbon nanotubes(MWCNTs) with volume fraction of 19.5% reinforced AZ80 magnesium matrix composites were prepared by friction stir processing(FSP). The microstructures of the composites were investigated. The distribution and stability of MWCNTs in the composites were investigated. The structural feature of the interface between MWCNTs and matrix was analyzed. The results show that the stability of MWCNTs in matrix is enhanced by multi-pass FSP. The nanocrystals with size of about 5 nm form in the composites. The multi-walled structures of MWCNTs along the diameter direction are not damaged by multi-pass FSP. There are a few Al4C3 phase in the composites after 7 passes by FSP. MWCNTs and magnesium matrix are joined in the form of semi-coherent interface.