Abstract

In order to solve the problem of agglomeration of graphene in preparation of composites, GN-CeO₂ powders with even dispersion were obtained by a hydrothermal reduction method, which involved modifying the surface of acidified graphene by cerium nitrate. Then, Al/GN-CeO₂ composite powders and materials were prepared by high-energy ball milling and vacuum hot pressing, respectively. The details were investigated, including the effect of modification process on the surface morphology and functional groups of graphene and modification time on the properties of Al/GN-CeO₂ composites. The result shows that the functional groups and defects of graphene were added by the treatment of acidification process, which is beneficial to the composite of graphene and CeO₂ particles. The quantity of CeO₂ deposition on graphene surface increased with the duration of hydrothermal reduction time. After 6 h modification, the properties of the composites performed best. Compared with Al/GN composites, the tensile strength of the modified composites was increased from 284 MPa to 321 MPa; and the tensile strain rate of the modified composites was increased to 12.3%；the hardness of the modified composites was increased from 97.1 Hv to 99.5 Hv；the conductivity of the modified composites was increased from 29.84%IACS to 33.21%IACS.

摘要

为了解决复合材料制备过程中石墨烯的团聚问题，采用硝酸铈对酸化石墨烯表面进行改性的水热还原法制备了分散均匀的GN-CeO ₂粉体。然后，分别通过高能球磨和真空热压制备Al/GN-CeO ₂复合粉体和材料。详细研究了改性过程对石墨烯表面形貌和官能团的影响以及改性时间对Al/GN-CeO ₂复合材料性能的影响。结果表明，酸化工艺处理增加了石墨烯的官能团和缺陷，有利于石墨烯和CeO的复合_2个粒子。石墨烯表面的CeO ₂沉积量随着水热还原时间的延长而增加。改性6 h后，复合材料的性能表现最好。与Al/GN复合材料相比，改性复合材料的拉伸强度从284 MPa提高到321 MPa；改性复合材料的拉伸应变率提高到12.3%；改性复合材料的硬度从97.1 Hv提高到99.5 Hv；导电率从29.84%IACS提高到33.21%IACS。