A Novel Modeling Method to Study the Oxide layer effect on Metallic Bonding in Cold Gas Dynamic Spray Process

Understanding and predicting material behavior in high strain rate processes, such as cold spray (CS), has been a major endeavour for decades. CS process particularities (solid state deposition under high strain rates and low temperatures) make it unique and more investigations are required for complete physical understanding. Investigations of material interactions at the substrate/coating interface during impact are still required to expand the process knowledge. Although several studies have examined substrate/coating interactions, none of them used a holistic approach to predict the occurrence of localized metallurgical bonding at the contact area.

In this study, a new physically-based finite element approach is proposed to model and predict the superficial oxide layer removal and the occurrence of localized metallic bonding during particle impacts. The process physics, based on explosive welding theory and experiments, and method implementation is presented. Prediction of critical velocity of copper is obtained and compared to experimental data to validate the model. Moreover, the model is also able to show the bonding locations at the interface between particle and substrate. The predicted bonding locations were compared with experimental data from literature for several metals, and comparison show fairly good agreement.