Simulation of spatial ordering of powder mixture particles when packed in square matrices using an example of monodisperse balls

Abstract

The peculiarities of self-ordering of large particles of powder mixture components with layer-by-layer pressing of long billets used in material production by the method of self-propagating high-temperature synthesis (SHS) are studied using the example of structure formation at compaction of thin layers of a model system of monodisperse calibrated solid balls (1 mm in diameter). In unilateral axial compaction, the case of packing of thin layers of balls (containing 1–5 monolayers) in a square matrix (with a ratio of the transverse dimension of the matrix to the diameter of the ball ∼14) is considered at low pressures that do not cause significant deformation of the balls. In the disperse system under study, a structural ordering of the particles occurs with a characteristic stepped view of the curve of the compact height dependence on the number of balls in the initial charge of balls. With an increase in the number of balls in the charge, the density of thin layers changes periodically during the compaction. In the compacts, fragments of structures in which the particles are arranged orderly like regular packing of ideal balls appear. The square shape of the matrix provides the formation of fragments of rhombohedral and cubic packing. The influence of nonuniform distribution of the initial charge of balls inside the matrix on the structuring of thin layers during compaction is considered.