Microstructure and mechanical properties of graphene/Al composites

Graphene and pure aluminum powders were firstly mixed thoroughly two step methods, namely ethanol solution dispersion and ball milling. Then, the cold pressing and vacuum hot pressing sintering combination process were applied to fabricate graphene/Al composites. The microstructure and mechanical properties of graphene/Al composites with different contents of graphene, and the morphologies of the composite powders were investigated by scanning electron microscope, X-ray diffractometer, electronic universal testing machine and hardness tester, respectively. The results show that the graphene uniformly disperses in Al powders using two step methods. Graphene/Al composites are compact, and the graphene nanosheets effectively distribute in the aluminum matrix and present well interface with aluminum matrix. The strength and hardness of graphene/Al composites increase with increasing the content (0.5%-2%, volume fraction) of graphene. When the graphene content is 1%, the composites present the best comprehensive mechanical properties than the others. The strength and hardness of graphene/Al composites reach up to 199 MPa and 82.95HV, compared to aluminum matrix, increased by 99% and 113%, respectively. ©, 2015, Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals. All right reserved.