Rapid solidification of a plasma-sprayed ceramic coating melted by a CO2 laser

Abstract
Successful modeling of the solidification process during laser melting has been achieved by numerical solution of a one‐dimensional heat transfer equation. Good agreement with experiments performed on ZrO2‐8 wt % Y2O3 coating is demonstrated. Radiation heat loss from the surface to the environment is found to be important to the microstructure of the solidified coating. The calculation provides a plausible explanation of the experimental observation that a remelted layer usually consists of an equiaxed layer on top of a columnar zone.