Analysis of recrystallization behavior of shot peened graphene reinforced Al composites during isothermal annealing by X-ray diffraction method

Abstract

Graphene reinforced Al matrix composites (G/Al) with high mechanical property was successfully reported. However, there are quite limited studies about the recrystallization behavior of these new composites after plastic deformation. Here, the recrystallization behaviors of shot-peened surface layer of G/Al composites and Al during isothermal annealing were investigated by using X-ray diffraction line profile analysis method. The microstrain, domain size, dislocation density at different annealing conditions were calculated. The results revealed that besides annealing temperature and time, the existence of graphene reinforcement also played an important role for its microstructure evolution. Based on the results of X-ray diffraction line profile analysis, the microstrain relaxation energy and recrystallization activation energy of G/Al composites and Al were calculated by computer regression analysis, respectively. It showed that microstrain relaxation energy and recrystallization activation energy of G/Al composites were higher than that of Al, which can be ascribed to the reinforcement's impeding movement of dislocations, grain and subgrain boundaries in the process of recrystallization. The effect of graphene reinforcement on the variation of relative texture coefficient and microhardness was also distinct. Based on above results, it can be concluded that the existence of graphene reinforcement may enhance the thermostablity of deformed G/Al composites.