In the thermal spraying process, the process for the molten metal particles to hit against matrix to form coating
experiences great change temperature. Since the coating materials has different thermal physical properties with the
matrix materials, the residual stress is surely left in the coating. Much bigger residual stress not only restricts coating
thickness but also primarily affects coating binding strength. Having analyzed reason for residual stress in the thermal
spraying coating and matrix, the theoretical model of arc spraying 3Cr13 molten drop impact stress is built and numerical
simulation is done for this theoretical model. The result indicates that: the faster the molten drop speed is, the greater the
pressure that matrix produces. When the molten drop's collision speed is 100m/s, it is not obvious for the matrix's
pressure stress and when the collision speed is increased to 200m/s, the pressure stress produced in the matrix can
maximize 5500Mpa; the faster the molten drop's collision speed is, the higher extent the molten drop's flattening is,
which is more beneficial to increase coating’s bonding strength. The radius for the molten drop in the radius of 35μm
becomes 80~110μm after collision and the flat ratio of the molten drop particle is about 3. The theoretical analysis is
consistent with the experiment result.
Spherical drop impact on solid surfaces: Un-damped oscillation theoretical model