Investigation on mechanical properties of nanofoam aluminum single crystal: using the method of molecular dynamics simulation

摘要

In this research, the mechanical behavior of aluminum nanofoam was studied by the method of molecular dynamics simulation. The effective parameters in mechanical properties such as porosity, pore size, temperature, and strain-rate were investigated. The results showed that Young's modulus, yield strength, and ultimate tensile strength were increased by decreasing the porosity and pore size. To accurately calculate the Young's modulus (E_s), the yield strength (σ_(YS)) and the ultimate tensile strength, combining the stress-strain curves with the potential and kinetic energy-strain curves was suggested as a standard method. The investigations about the effects of temperature and strain-rate on the tensile behavior showed that increasing temperature cause decrease in E_s, σ_(YS), and σ_(UJS) of foams. Moreover, the σ_(UTS) increased significantly while the E_s and the σ_(YS) of the samples exhibited minor change with an increase in strain-rate. Nanofoam failure also occurred by stress localization, nucleation, and growth of cracks on the surface of pores.