Crystal plasticity finite element investigation of deformation of single crystal copper during cold spray

Over the past decade, cold spray (CS) process quickly emerges as an attractive additive manufacturing technology to fabricate individual components along with repairing damaged components. In comparison with fusion-based high-temperature additive manufacturing processes, the feedstock remains solid throughout the deposition process with low oxidation, minimal microstructural and chemical degradation in the final component. Considering the small size of cold spray particles (10-50 mu m), the dependence of plastic behaviour on the crystalline orientation at high-velocity impacts needs to be investigated. In this work, we present a crystalviscoplasticity model with Johnson-Cook type strain-rate and temperature dependence developed for metals with low stacking fault energy (SFE). Through the numerical study, a dependence of the dominating bonding mechanism on the crystal orientation was observed. Some orientations showed higher localized plastic deformation than others. For instance, for FCC copper particle, [111] orientation often exhibited better bonding characteristics than [100] and [110] orientations. Additionally, the effect of substrate crystallographic orientations on particle bonding was also clarified in this work. The incorporation of the explicit microscopic information in the present study provides important insights into the role of crystal-scale micro-mechanics in the deformation behaviour during cold spray additive manufacturing.