A Smoothed Particle "Hydrodynamics (SPH) procedure for simulating cold spray process - A study using particles

Cold spray process has been of great interest in coating and additive manufacturing because it does not need heat supply during impact. Cold spray generally uses particles of diameters 10 mu m to 50 mu m traveling at velocities of 300 m/s to 1200 m/s, and it takes place at very small time and length scales. Thus, it becomes difficult to observe the detailed process experimentally. The primary objective of this study is to use SPH and highlight its capability for modeling cold-spray process. A novel way of establishing boundary conditions using Monaghan type 2 particles is adopted in this study. Additionally,our SPH model includes failure modeling for copper particle impacts. Particles of different sizes and at different angles are studied to reveal the effects of impact which includes recording effective plastic strain, deformation and temperature. It was found that larger particles had greater ability to adhere to the surface of the substrate and an impact angle between 80 degrees and 90 degrees has higher chances of adherence to the substrate. An increase in maximum effective plastic strain is seen which causes thermal softening leading to plastic flow of material. This fluid-like flow causes adherence of the particle on the substrate. Finally, the in-house SPH procedure is extended to simulate three-dimensional cold spray problems with multiple particles.