搅拌摩擦加工碳纳米管增强7075铝基复合材料的疲劳性能

Fatigue Property of Carbon Nanotubes Reinforced 7075 Al Alloy Composite Prepared by Friction Stir Processing

摘要:

采用搅拌摩擦加工方法制备了碳纳米管增强7075铝基复合材料，研究了复合材料显微组织和疲劳性能。结果表明：复合材料晶粒细小，增强相碳纳米管在基体中分散均匀。随碳纳米管体积分数的增加，碳纳米管在基体中的分散程度降低。复合材料的疲劳性能高于基材，且随着碳纳米管含量的增加，复合材料的疲劳性能逐渐提高，但发现其抗拉强度呈现逐渐减小的趋势。复合材料中存在少量的大尺寸金属间化合物、非金属夹杂、片状氧化物等缺陷对复合材料的疲劳性能造成不利影响。

Abstract:

Carbon nano-tubes (CNTs) reinforced 7075 aluminum alloy matrix composite was prepared by friction stir processing, and the microstructure and fatigue properties of the composite were investigated. The results show that the grain size of the composite is much finer and MWCNTs (multi-walled carbon nano-tubes) are uniformly distributed in matrix material. Along with the increase of volume fraction of MWCNTs, the dispersion becomes worse and the fatigue property of the composite is higher than that of the annealed 7075 aluminum alloy matrix. Meanwhile, the fatigue property increases with the increase of MWCNTs content, but the tensile strength decreases gradually. Defects of large size intermetallics, non-metallic inclusion and chip-like metal oxide are observed in the composite which could strongly reduce the fatigue of the composite.