单壁碳纳米管/7075铝合金复合材料的组织和力学性能研究

Research on Microstructure and Mechanical Properties of Single-walled Carbon Nanotubes/7075 Composites

采用超声分散单壁碳纳米管,通过高能球磨混合粉末,利用放电等离子烧结来制备单壁碳纳米管/7075铝基复合材料,研究不同单壁碳纳米管含量对7075铝合金组织和力学性能的影响。结果表明,随着单壁碳纳米管的增加,复合材料的晶粒尺寸先变小再变大,材料的强度和硬度先提高后降低。当单壁碳纳米管的质量分数为0.2wt%时,复合材料的晶粒尺寸达到最小、最均匀,其抗拉强度、硬度也达到最大值,分别为415.2 MPa、142.94 HV0.1,分别为基体材料的1.67、1.42倍。主要的强化机制是第二相弥散强化,第二相主要有单壁碳纳米管和Mg(Zn,Al,Cu)2。

The single-walled carbon nanotubes(SWCNTs)/7075 aluminum matrix composites were prepared by ultrasonic dispersion, high-energy ball milling and discharge plasma sintering. The effects of different SWNTs contents on the microstructure and mechanical properties of 7075 aluminum alloy were studied. The results show that with the increase of single-walled carbon nanotubes, the grain size of the composites decreases first and then increases, and the strength and hardness of the composites increase first and then decrease. When the mass fraction of single-walled carbon nanotubes is0.2wt%, the grain size of the composite reaches the minimum and the most uniform, and its strength and hardness also reach the maximum, which are 415.2 MPa and 142.94 HV0.1, respectively, which are 1.67 and 1.42 times of the matrix material.The main strengthening mechanism is dispersion strengthening of the second phase, which mainly consists of single-walled carbon nanotubes and Mg(Zn, Al, Cu)2.