Powder Technology, Vol.325, 651-658, 2018
Controlled kinetic Monte Carlo simulation of laser improved nano particle deposition process
Thin film coating is important in many applications such as electrodes, sensors, and energy devices. Nano particle deposition is one of the most used additive manufacturing processes for coating. It has advantages of efficiency, cost effectiveness, and ease of controlling film properties. Recent experimental studies showed that laser can enhance the efficiency of the deposition process. However, there is still a lack of fundamental understanding of the laser treatment effect on nano particles, which makes process control difficult and ad hoc. In this research, the effect of laser treatment on morphological change of films in the nano particle deposition system is studied with controlled kinetic Monte Carlo (cKMC) simulation. cKMC is a generalized version of classical kinetic Monte Carlo, which can be used to simulate both controlled and self-assembly processes at atomistic level with larger sizes and longer time scales than molecular dynamics. In this work, a coarse-grained cKMC model is constructed to simulate diffusion, laser irradiation, and deposition processes simultaneously. The simulation model is calibrated with experimental data. Different laser irradiation conditions on alumina particles are studied, which result in different thickness and porosity of the deposited layers. A Gaussian process regression modeling approach is also developed for model validation with the consideration of observation bias and discrepancy. Simulation results are in good agreement with the experimental results. (C) 2017 Published by Elsevier B.V.
Keywords:Laser sintering;Nano particle deposition system;Controlled kinetic Monte Carlo;Thin film analysis;Porosity;Gaussian process regression