Combined structural and CFD finite element simulation of the cold-spray process

Integration of the cold spray process into modern industrial workflows requires the creation of a “digital twin” to obtain information on process conditions starting from final requirements. Although cold spraying is fairly well understood, there are still some hurdles toward achieving that goal. There is limited “backward” integration between structural finite element (FE) models of particle impact, which predict optimal impact conditions, and CFD FE models of gas-particle in-flight dynamics, which predict how those impact conditions depend on process settings.

Moreover, most simulations of particle impacts employed relatively simple elastic-plastic constitutive equations like the Johnson-Cook model, which have known limits in capturing the mechanical response of metals at the extremely large strain rates involved in cold spraying.

In the present work, we therefore simulated the deposition of austenitic stainless steel particles onto an identical substrate employing a more refined constitutive model, the modified threshold stress (MTS) mode, to capture high-rate phenomena more reliably. As the impact simulations yielded predictions for optimal impact conditions, these were then coupled with a CFD model to find the process parameters that allow achieving those conditions.

The predictions of the impact and CFD models were both verified through single-particle and coating deposition experiments.