Examining solid-state sintering of AlCoCrFeNi multi-principal element alloy by molecular simulations

Abstract

With the emergence of solid-state sintering techniques for metal additive manufacturing of multicomponent alloys, understanding the fundamental sintering mechanisms is vital for effective process control. Here, we employ molecular dynamics simulations to investigate the mechanisms involved during solid-state sintering of AlCoCrFeNi multi-principal element alloy. Our results reveal that the cross migration of atoms between the surface of powder particles promotes neck growth while minimizing the surface free energy. This phenomenon is mediated by a transition from BCC to amorphous phase resembling a pre-melt and assisting in the densification as a function of temperature. Stress–strain analysis on the alloy single crystal at room temperature suggests that permanent plastic deformation occurs with a gradual phase change to FCC predicting a tensile strength of ∼ 1547 MPa at the onset of yield and a peak stress of 2267 MPa.