碳纳米管-Ti3AlC2/AZ91D复合材料的微观组织及力学性能

采用化学镀铜的方法对增强相碳纳米管(CNTs)和Ti₃AlC₂进行表面改性，热压烧结制备了CNTs-Ti₃AlC₂/AZ91D复合材料，研究了其微观组织和力学性能的变化及增强机制。结果表明:CNTs-Ti₃AlC₂/AZ91D复合材料内部主要物相为CNTs、Ti₃AlC₂、Mg和Al₁₂Mg₁₇，增强相均匀分布在基体内，在增强相与基体的界面处存在U相(MgAlCu)，使二者界面结合良好。当增强相CNTs 和Ti₃AlC₂含量分别为1wt%和25wt%时，较镁合金AZ91D，CNTs-Ti₃AlC₂/AZ91D复合材料的弹性模量、拉伸强度、屈服强度和延伸率分别提高了120.30%、25.72%、126.50%和36.84%，弯曲强度和压缩强度分别为337.92 MPa和436.27 MPa。CNTs-Ti₃AlC₂/AZ91D复合材料的断裂方式表现为脆性断裂，其强化机制主要为热配错强化、Orowan强化和细晶强化机制。 

Micro-morphology and mechanical properties of carbon nanotubes-Ti3AlC2/AZ91D composites

Carbon nanotubes(CNTs) and Ti₃AlC₂ reinforced phase was surface modified by electroless copper plating. The CNTs-Ti₃AlC₂/AZ91D composites was prepared by hot pressing (HP) sintering. The microstructure, mechanical properties and strengthening mechanism of the CNTs-Ti₃AlC₂/AZ91D composites were studied.The results indicate that the main physical phases in the CNTs-Ti₃AlC₂/AZ91D composite are CNTs, Ti₃AlC₂, Mg and Al₁₂Mg₁₇, and the reinforced phase is uniformly distributed in the matrix. There is a U phase (MgAlCu) at the interface between the reinforced phase and the matrix, which can make the interface of the two well combined. When the reinforced phase content is CNTs (1wt%) and Ti₃AlC₂ (25wt%), compared with magnesium alloyAZ91D, the elasticity modulus, tensile strength, yield strength and elongation of the CNTs-Ti₃AlC₂/AZ91D composites are increased by 120.30%, 25.72%, 126.50% and 36.84%, respectively, and the flexural strength and compression strength are 337.92 MPa and 436.27 MPa. The fracture mode of the CNTs-Ti₃AlC₂/AZ91D composites is brittle fracture, and the strengthening mechanism is mainly thermal mismatch strengthening, Orowan strengthening and fine grain strengthening.