Experimental and numerical modeling for flattening and rapid solidification with crystallization behavior of supersonic ceramic droplets [post]

Y. Wang, Y Bai, K Wu, J Zhou, M G Shen, Y Ming, Q. Liu, N J Chong, Y W Sun, Y B Hu, X J Du, Z B She
2020 unpublished
Successive impingement of supersonic droplets after refining in plasma jet usually forms a fine-lamellar structured coating with high mechanical properties. However, the comprehensive process (such as flattening, rapid solidification and crystallization) of high-velocity impact of refined droplets is difficult to understand. In this study, an experimental study showed that the content of refinement droplets reached to 90 % and displayed the multi-scale equiaxed grains morphology at extremely
more » ... id solidification rate. Phase-field model revealed a hybrid coalescence growth of oriented attachment and migration of grains boundary under the dynamic temperature gradient. Furthermore, an optimized numerical model that consisted of the Navier-Stokes and energy balance equations coupled with the Cahn-Hilliard and phase-field model for growth orientation of grains was developed to accurately reproduce the comprehensive process of refined supersonic droplets. The size distribution and crystallographic orientation of columnar grains for single or two flattened droplets were in a good agreement with the experimental results. The interface between two-flattened droplets exhibited an epitaxial growth of columnar grains. This optimized model can be an effective method in predicting the flattening and solidification with crystallization behavior of droplets during plasma spraying.
doi:10.21203/rs.3.rs-79503/v1 fatcat:avjhfp7r7rd2xfv7uhd2xvc65e