Prediction of Particle Properties in Plasma Spraying Based on Machine Learning

Thermal spraying processes include complex nonlinear interdependencies among process parameters, in-flight particle properties and coating structure. Therefore, employing computer-aided methods is essential to quantify these complex relationships and subsequently enhance the process reproducibility. Typically, classic modeling approaches are pursued to understand these interactions. While these approaches are able to capture very complex systems, the increasingly sophisticated models have the drawback of requiring considerable calculation time. In this study, two different Machine Learning (ML) methods, Residual Neural Network (ResNet) and Support Vector Machine (SVM), were used to estimate the in-flight particle properties in plasma spraying in a much faster manner. To this end, data sets comprising the process parameters such as electrical current and gas flow as well as the in-flight particle velocities, temperatures and positions have been extracted from a CFD simulation of the plasma jet. Furthermore, two Design of Experiments (DOE) methods, Central Composite Design (CCD) and Latin Hypercube Sampling (LHS), have been employed to cover a set of representative process parameters for training the ML models. The results show that the developed ML models are able to estimate the trends of particle properties precisely and dramatically faster than the computation-intensive CFD simulations.