片状粉末冶金的石墨烯/铝基复合材料制备过程控制与力学性能

Graphene/Al composites have the characteristics of high strengthening efficiency, synergistic improvement of strong plasticity, and excellent comprehensive performance, which is expected to break through the bottleneck problem of poor strength- plasticity matching of metal matrix composites. However, the dispersion of graphene is an important issue that plagues the preparation of materials. The flaky powder metallurgy technology based on the mechanical ball-milling process can transform the spherical aluminum powder into flakes and realize the uniform dispersion of graphene. In this study, the mechanical ball-milling process was controlled by adding a process control agent (polydimethylsiloxane, PDMS) to prepare flaky Al powder, combined with pressure infiltration technology to prepare 0.6%(mass fraction) GNPs/6061Al composites. The results show that the diameter of flaky aluminum powder increases first and then stabilizes with the prolongation of milling time. As the viscosity of process control agent increases, the diameter of flaky aluminum powder is increased, and the flaky effect of aluminum powder is more obvious. At the same time, the viscosity of graphene defect content decreases first and then increases. Moreover, it is revealed that the graphene defects show a decreasing and increasing change pattern as the viscosity increased. Combined with the structure characterization and mechanical property test, the relationship between properties and structure is discussed, which has provided a reference for the subsequent preparation of graphene/Al composites.