The role of vibration time in interfacial microstructure and mechanical properties of Al/Mg bimetallic composites produced by a novel compound casting

Abstract

A simple mechanical vibration was used to enhance interface bonding of the Al/Mg bimetallic composites produced by a novel lost foam compound casting in this study. The effect of vibration time on interfacial microstructure and mechanical properties of the Al/Mg bimetallic composites was investigated. The results show that the vibration time had a significant effect on the interfacial microstructure and mechanical properties of the Al/Mg bimetallic composites. With the increase of the vibration time, the cooling rate during the solidification was increased, and the thickness of intermetallic compounds (IMCs) layer at the interface of the Al/Mg bimetallic composites was decreased. This resulted in the decrease of A3Mg2 and Al12Mg17 brittle phases, and the Mg2Si phase at the interface was refined with a distribution change from agglomeration to dispersion. When the vibration time was 300 s, the vibration fully affected the formation and solidification process of the IMCs layer of the Al/Mg bimetallic composites, and had an obvious effect on the reduction of the brittle phases as well as the improvement of the size and distribution of the Mg2Si phase. As a result, the shear strength of the Al/Mg bimetallic composites was the highest, reaching 47.49 MPa, which was 51% higher than that of the Al/Mg bimetallic composites without vibration.