热处理对MWCNTs/AZ80镁基复合材料组织和力学性能的影响

Effect of Heat Treatment on Microstructure and Mechanical Property of MWCNTs/AZ80 Composite

摘要:

采用搅拌摩擦加工法制备了不同体积分数碳纳米管增强AZ80镁基复合材料，考察了固溶+时效热处理对复合材料的微观组织和力学性能的影响。结果表明：镁基复合材料组织致密，晶粒细小，其中的碳纳米管均匀分布；热处理导致碳纳米管与AZ80基体界面上有A13Ni2化合物生成，改善了界面结构；复合材料的抗拉强度随碳纳米管体积分数的增加逐渐增加，固溶+时效处理后的复合材料的抗拉强度有所提高，影响MWCNTs/AZ80复合材料力学性能的主要因素是碳纳米管与镁基体之间的界面结合情况

Abstract:

AZ80 magnesium based composites strengthened by multi-walled carbon nanotubes (MWCNTs) of different volume fractions were fabricated by friction stir processing (FSP) and the effect of heat treatment on microstructure and mechanical property of MWCNTs/AZ80 were investigated. The results show that the Mg-based composites are dense with fine grains, in which MWCNTs distribute uniformly. A13Ni2 intermetallic compounds are formed on the interface between the MWCNTs and the magnesium matrix, leading to a sound bonding condition. The tensile strength of the composites increases with the increase of volume fraction of the MWCNTs, and it is also improved by the post heat treatment of solid solution and aging. The major factor affecting the mechanical property of the MWCNTs/AZ80 is the interface structure between the MWCNTs and the magnesium matrix