Simulation of Solid Particle Impact Behavior for Spray Processes

Abstract

Several thermal spray processes developed recently are characterized by relatively low temperature and higher velocity of sprayed particles. They include cold spray, high velocity oxy-fuel spray, and warm spray, in which majority or all the sprayed particles are in solid phase when impinging onto the substrate surface. Therefore, in order to understand the coating formation process of such processes, detailed knowledge concerning impact phenomena of a solid particle is essential. It is generally accepted that there exists a minimum velocity beyond which a particle adheres to the substrate and this velocity is called the ''critical velocity''. How the critical velocity depends on various materials and process variables is not fully understood yet. In this study, analysis of a metal particle impacting onto a metal substrate was carried out by using a dynamic finite element code (ABAQUS). Effects of a substrate and a particle temperature on the critical velocity were numerically studied. Also, effects of thermal conduction on the simulation results were discussed. It was found that critical velocity decreases with 1) higher stiffness of the substrate, 2) higher particles temperature, and 3) greater particle size.

Warm spraying—a novel coating process based on high-velocity impact of solid particles

“…Figure 12 shows the sequence of the deformation of a copper particle impacted onto a substrate for a particle diameter of 50 µm, a particle initial temperature of 293 K, and an initial velocity of 550 m s −1 calculated by Yokoyama et al [26]. The material parameters used in this calculation are listed in table 3.…”

Effect of Feedstock Powder Characteristic on the Properties of Super-Sonic Flow Deposited Cu Coating Layer

“…10) As a result, small particles can induce strong plastic deformation of the particle 8,11) and thus results in a dense microstructure of the coating layer. Figure 5 shows the porosity variation with annealing heat treatment (373 K$773 K/1 h) in two different powder coating layers (A and B).…”

Molecular Dynamics Simulation on the Modification of Crystallographic Orientation in Fragmented Particles in the Aerosol-Deposition Process

“…In addition to the differences in size and incident speed of the particle, previous studies [7][8][9][10][11][12][13][14][15][16][17] have different standpoint for the particle orientation. These studies do not pay attention to crystallographic orientation of the incident particle, therefore assumed particle orientations were not described or simply mentioned 8,12,13) as 'at random'.…”

“…[7][8][9][10][11][12][13][14][15][16][17] Most of these studies deal with clusters or small particles composed of less than 2000 atoms at higher impact energies than 1 eV/ atom. In such conditions, crystal structures of incident particles are completely destroyed.…”