Preparation of graphene coated aluminum composite powders by high-energy ball milling

Abstract The preparation of composite powders has an important impact on the properties of the synthesized bulk materials. In this work, graphene coated aluminum composite powders were successfully prepared by high-energy ball milling. The microstructure of graphene/aluminum mixed powders was characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The effects of the micro-morphology of the composite powders and the ratio of the ball to the particle size of the graphene-coated aluminum composite powders were analyzed in detail. The results show that graphene can be uniformly dispersed in aluminum powder without significant agglomeration in the case of ball milling parameters with a ball-to-powder ratio of 5:1. When the ratio of ball to material is 6:1, the dispersion effect was not so obvious. However, the level of agglomeration in the composite powders at ratios 7:1 and 8:1 differed respectively; some particles were deformed and the dispersion effect was reduced. The particle size of the graphene coated aluminum composite powder increased with the increase of ball to material ratio. Thermodynamic analysis of the interface reaction between graphene and aluminum composite powders shows that the maximum content of graphene microflakes on the surface of aluminum powder is 0.3wt%.