Molecular Dynamics Study of Compressive Properties and Atomistic Behavior of Boron Nitride Nanosheets Reinforced in Aluminum Matrix Composites

Boron nitride nanosheet (BNNS) has been widely used in aluminum (Al) matrix composites because of its extraordinary mechanical properties. However, the strengthening mechanism of BNNS in the Al matrix was seldom studied. In this work, three different BNNS/Al models were constructed, and the effect of BNNS’s volume fraction on the compressive properties of BNNS/Al composites was investigated using molecular dynamics. With the increase of BNNS’s volume fraction, the ultimate strength and Young’s modulus are significantly enhanced, but the critical strain decreases gradually. The stress distribution reveals the contribution of the BNNS and Al matrix. In addition, the atomic configurations were captured to analyze the reason for the decrease in critical strain. The interaction between the Al matrix and BNNS is evident at the interface. This results in the great deformation of the Al matrix in the direction perpendicular to the BNNS. Since BNNS can transfer the compression load and block the propagation of stacking faults in the Al matrix, BNNS/Al composites have excellent compression properties in both the elastic and plastic stages.