Molecular Dynamics Study on the Sintering Mechanism and Tensile Properties of Novel Cu Nanoparticle/Graphene Nanoplatelet Composite Solder Paste

The sintering process of Cu nanoparticle (Cu NP)/graphene nanoplatelet (GNP) composite solder paste was thoroughly investigated in this work through molecular dynamics simulations. The tensile properties of the sintered Cu NP/GNP composite solder paste were considered by using the uniaxial quasi-static tensile simulation method. The impact of sintering temperature, strain rate, and GNP addition on the tensile properties of Cu NP/GNP sintered structures was thoroughly investigated. The lattice structure, dislocation evolution, and atomic diffusion of the molecular dynamics results were analyzed using the common neighbor analysis (CNA), dislocation extraction algorithm (DXA), and mean square displacement (MSD) methods. The results of the post-processing analysis showed that the addition of GNP and the sintering temperature have an important influence on the mechanical properties of Cu NP/GNP sintered structures. In addition, the incorporation of GNP can significantly improve the mechanical properties of sintered Cu NP/GNP composite solder paste. More specifically, the tensile strength and fracture strain of the sintered composite solder paste will be increased by increasing the tensile strain rate. The strengthening mechanism of the sintered Cu NP/GNP composite solder paste can be attributed to the dislocation strengthening mechanism. Our study provides valuable insight for the development of high-performance composite solder paste with enhanced mechanical properties.