(南京工程学院 材料工程学院 江苏省先进结构材料与应用技术重点实验室，南京 211167)
摘 要: 采用电化学加超声剥离制取微纳石墨烯片，通过粉末冶金制备石墨烯增强铝合金。使用纳米压痕和摩擦磨损试验机对样品的纳米硬度、弹性模量、室温蠕变以及摩擦性能进行研究。结果表明：铝合金的纳米硬度和弹性模量随着微纳石墨烯片含量的增加呈线性提高；当微纳石墨烯片含量为0.20%(质量分数)时，石墨烯增强铝合金的纳米硬度和弹性模量比纯铝合金的分别提高66%和52%，室温平均蠕变度在保载阶段为纯铝合金的54.56%，在稳定阶段平均蠕变速率仅为纯铝合金的1/10，摩擦因数随微纳石墨烯片含量的增加而逐渐降低。微纳石墨烯片的加入使得晶粒细化、产生高位错密度和晶格畸变，提高了石墨烯铝合金复合材料的纳米硬度以及弹性模量，微纳石墨烯片对部分可动位错钉扎提高了铝合金抗蠕变性能，微纳石墨烯片存在自润滑性提高了铝合金摩擦性能。
关键字: 铝合金；微纳石墨烯片；电化学；纳米压痕；室温蠕变
（Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, School of Material Science and Engineering, Nanjing Institute of Technology, Nanjing 211167, China）
Abstract:Graphene nanosheets (EG) were produced by electrochemical and ultrasonic method. Graphene aluminum alloy composites were prepared via powder metallurgy method. Nano-hardness, elasticity modulus, room temperature creep and tribological properties of the samples were investigated by using nano-indentation and friction wear testing machine, respectively. The nano-hardness and elasticity modulus increase linearly with the increase of EG content. When EG content is 0.20%, nano-hardness and elastic modulus of graphene aluminum alloy composite are 66% and 52% higher than those of aluminum alloy, respectively. The average creep degree of the aluminum alloy composites with 0.2% EG in holding stage is 54.56% of aluminum alloy, and the average creep rate of the aluminum alloy composites with 0.2% EG in steady-stage is only 1/10 of that of aluminum alloy. The friction coefficients of graphene aluminum alloy composites decrease with the increase of EG content. The nano-hardness and elasticity modulus of graphene aluminum alloy composites are enhanced through grain refinement, high dislocation density and lattice distortion. The creep resistance properties of graphene aluminum alloy composites are improved via EG pinning the movable dislocation. And the friction properties are improved because of the self-lubricating properties of the EG.
Key words: aluminum alloy; graphene nanosheets; electrochemical method; nano-indentation; room temperature creep
