Chapter Three - Molecular dynamics modeling of sintering phenomena and mechanical strength of metal particles

Abstract

This chapter presents an atomistic scale model on sintering of metal particles in power bed fusion sintering process. Both sintering phenomena and mechanical strength of sintered particles are simulated using molecular dynamics. A two-particle atomistic model is developed to investigate the diffusion of atoms during nickel sintering. The diffusion of particle surface is higher than the particle core. The sintered model shows a fivefold twinning structure at 1200 K, and two parallel twin boundaries at 1300 K. The mechanical properties of nickel nanoparticles sintered at various heating rates are investigated using uniaxial tensile test simulations. The results show that higher heating rate during sintering increases the mechanical strength of the sintered material. Deformation mechanism of sintered structures is illustrated from the correlation between stress and dislocation evolution.