Hollow　yttrium-stabilized　zirconia　(YSZ)　particles,　which　are　often　used　to　prepare　high　porosity　coatings　in　industry,　hit　substrate　at　a　fully　molten　state　or　semi-molten　state　due　to　the　high　temperature　gradient　of　particles　caused　by　the　low　thermal　conductivity.　Considering　the　hollow　solid　core　large　deformation　and　liquid　solidification　during　the　deposition　of　semi-molten　hollow　particles　(SMHPs),　a　fluid-structure　interaction　model　described　by　the　coupled　Eulerian　and　Lagrangian　(CEL)　method,　is　developed　and　validated　to　investigate　the　spreading　results　in　thermal　spraying.　The　empirical　formula　of　dynamic　viscosity　based　on　the　ABAQUS　CEL　method　is　proposed　and　verified　for　simulation　of　the　liquid　YSZ　spreading　and　solidification.　The　compression　ratio　and　plastic　dissipation　are　calculated　to　reveal　flattening　and　buckling　phenomena　of　hollow　solid　core　with　different　initial　velocities　and　hollow　radius.　Moreover,　a　double-SMHP　impact　model　is　established　to　simulate　the　interaction　of　particle-particle-substrate,　and　the　effect　of　flattening,　buckling　and　structural　self-contact　on　porosity　is　analyzed.　Numerical　simulation　results　show　that　hollow　solid　core　large　deformation　induces　instability　accompanied　by　flattening,　buckling　or　structural　self-contact,　which　results　in　the　reduction　of　layer　porosity.　©　2024　IOP　Publishing　Ltd.