Microstructure and mechanical properties of ADC12 composites reinforced with graphene nanoplates prepared by ultrasonic assisted casting

Microstructure and mechanical properties of ADC12 composites reinforced with graphene nanoplates (GNPs) prepared by high-intensity ultrasonic assisted casting were investigated. The results indicated that high-intensity ultrasound can promote the uniform distribution of GNPs in the melt, resulting in refining the alpha(Al) phase and Si phase. The optimal addition of GNPs was 0.9 wt.%, and the optimal ultrasonic time was 12 min. The tensile strength, the yield strength and the hardness of the composite produced under the optimal parameters were 256.8 MPa, 210.6 MPa and HV 126.0, respectively, which increased by 30.5%, 42.7%, and 34.8% compared with those of the matrix, respectively. After adding the GNPs, the fracture mechanism gradually turned from a brittle fracture to a ductile fracture. The good interface and distribution allowed GNPs to play the role in fine grain strengthening, dislocation strengthening and load transfer strengthening effectively.