Numerical modeling and deposition pattern simulation for the whole process of electrohydrodynamic atomization printing

Electrohydrodynamic atomization printing (EHDAP) is an additive manufacturing technology of high interest due to its multiple deposition modes and controlled deposition on arbitrary surfaces. However, there are multiple rheological states as well as strong influence of parameters during the printing process, and the deposition pattern is prone to discontinuities, scattering, and other undesirable qualities. At present, the mechanism of the influence of operating parameters on the deposition pattern is not clear enough. The lack of a full-process analytical model prevents direct studies of deposition patterns and quality. This study proposes a hybrid analysis method based on the three-dimensional Lagrangian particle model. The initial injection parameters and the fission of the charged droplets are considered. The whole process of printing was simulated by this method, and the accuracy of the simulation was verified by comparison experiments. The simulation result shows that the jet state and droplet size distribution are the main reasons affecting the variation of the deposition pattern. The effects of operating parameters on the deposition pattern and pattern range were analyzed. BoE-Q*, BoE-U*, and Q*-U* transition phase diagrams about four deposition patterns were investigated, where BoE is the dimensionless electric Bond number, Q* is the dimensionless flow rate, and U* is the dimensionless printing velocity. For the first time, the operating intervals for the satellite-free droplet deposition patterns are given. Fabrication results based on satellite-free droplet intervals exhibit high quality. This work provides general laws and high-quality print intervals of operating parameters for optimizing EHDAP.