Application of a holistic 3D model to estimate state of cold spray titanium particles

A validated three dimensional Computational Fluid Dynamics (Cm) model has been utilized to estimate the state of cold spray titanium particles before deposition. A holistic approach is adopted to predict particle velocity, temperature and location from the injection point to the moment of impact onto the substrate for a commercially available cold spray system. The behavior of particles between the nozzle exit and substrate surface is detailed for cold spray stagnation conditions of 800 degrees C, 3 MPa and 550 degrees C, 1.4 MPa. The particle size distribution of titanium powder is also considered. The 3D model predicts a complicated distribution of particles within the deposition zone that cannot be arrived at using current one and two dimensional models. The critical velocity and deposition efficiency of the titanium powder are quantified. The model estimated a significant improvement in deposition efficiency when the temperature of the titanium particle increased to 300 degrees C before impact. Merits of the 3D CFD model for the development of new materials and cold spray additive manufacturing are highlighted. (C) 2015 Elsevier Ltd. All rights reserved.