Current understanding of mechanisms of splat formation during thermal spraying are discussed. Schematic of influence of particle velocity on change of impact and forward pressure during particle-substrate interaction are given. The existence of three typical zones of particle-substrate contact is shown. These zones are: (1) central circle type mechanically activated by hammer and head pressure; (2) middle ring-shaped mechanically activated by head pressure and friction of spreading particle; (3) peripheral ring-shaped mechanically activated by friction of spreading particle. It is possible to estimate dimensions of these zones analytically. The stress distribution on particle-substrate contact during splat formation is discussed. It is shown that relative values of area for these zones depends from particle velocity. The presence of these typical zones during splat formation shown by conduction of special model experiments.