A 3D Multiscale Simulation of Microscale Deposition of Cold Spray Coatings for Establishing Predictive Correlations between Atomistic Material Properties and Spray Conditions

Optimization of coating microstructure and coating properties based on experimentation and without precise knowledge of microscale deposition process is complex and expensive process. The critical velocity needed for powders/particles to adhere and flow on impact is correlated to temperature rise and ability to flow on substrate are important unknowns for coating deposition. Currently, numerical simulations depend heavily on empirical parameterization schemes and simpler coating deposition models. Composite, amorphous alloys and multi-component mix of different precursors have further increased the complexity of a atomistic scale physics based microscale deposition model. The deposition process depends strongly on material response at high shear rates across a wide range of temperatures. Cohesive forces in the atomistic scale and material-dependent prediction of shear instabilities are important factors for creating multiscale model of deposition. A 3D multiscale model for massively parallel computing environment will be presented where particle trajectories are further investigated to study microscale impact, flow and deposition. Particle size effects on adhesion and dependence on alloy properties using atomistic molecular dynamics (MD) simulations will be demonstrated. Challenges for the multiscale simulation such as implementation of intermetallic reactions on deposition using MD simulations and fluid dynamics methods for characterization of temperature effects will be discussed.