Arc Spraying 3Cr13 Molten Drop Impact Stress Numerical Analysis

ABSTRACT

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.

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