Finite element modeling of fracture in ceramic micro-particles during composite cold Spray process

Cold spray provides a new and quick method for developing metal matrix composite coatings. The coating build-up process involves the acceleration of, a mixture of micron-sized metal and ceramic particles to impact the substrate at high velocities. The retention and fragmentation of the ceramic particles play a critical role in determining the coating properties and thus necessitate understanding the dynamic impact behaviour of brittle ceramic particles. This work examined the fracture behaviour of a polycrystalline ceramic particle upon impact on a metal substrate using systematic numerical simulations. Simulations have been carried out for different values of ceramic particle grain size and particle impact velocity. The results show that material failure occurs by the linking of wing cracks. The necessary conditions for fragmentation and retention probabilities of ceramic particles have been studied considering the effects of particle grain size and impact velocities. This study contributes important mechanistic knowledge towards understanding and predicting the ceramic retention behaviour and composite coating characteristics during metal-ceramic composite cold spraying.