Data-driven Overlapping Track Profile Modelling in Cold Spray Additive Manufacturing

Cold spray additive manufacturing is an emerging solid-state deposition process that enables large-scale component production at high rates. Control over geometry is important for reducing the development and growth of defects during the 3D build process and improving the final dimensional accuracy and quality of components. A machine learning approach has recently gained interest in modelling additively manufactured geometry. However, such a data-driven modelling framework lacks the explicit consideration of a depositing surface and domain knowledge in cold spray additive manufacturing. This study presents surface-aware data-driven modelling of an overlapping-track profile using a Gaussian Process regression model. The proposed Gaussian Process modelling framework explicitly incorporated two relevant geometric features (i.e., surface type and polar length from the nozzle exit to the surface) and a widely adopted Gaussian superposing model as prior domain knowledge in the form of an explicit mean function. It was shown that the proposed model provides better predictive performance than a Gaussian superposing model alone and a purely data-driven Gaussian Process model, yielding consistent overlapping-track profile predictions at all overlap ratios. By combining accurate prediction of track geometry with toolpath planning, it is anticipated that improved geometric control and product quality can be achieved.