Determination of the Temperature Distribution of a Substrate Exposed to a Moving Cold or Thermal Spray Heat Source

A three-dimensional transient heat conduction model was developed to evaluate analytically the surface temperature profile of the substrate that was exposed to the impingement of a moving time-dependent heat source such as a cold spray nozzle or thermal spray torch. The estimated surface temperature profile was compared to the experimental results of the surface temperature of an aluminium substrate under impingement of a moving air jet generated by a low-pressure cold spray system. Close agreement between the analytical model and the experimental data was found. It was also found that the speed of the moving heat source significantly affected both the profile and maximum temperature of the substrate. The non-dimensional Peclét number was considered to take into account the effect of the speed of the moving heat source, to broaden the application of the model to a wide range of materials and conditions. It was found that as the Peclét number increased, the thermal energy that was conducted into the substrate decreased. It was concluded that with knowledge of the Peclét number, the analytical model was capable of predicting the spatial and temporal surface temperature of the substrate exposed to a moving heat source produced by spray nozzles and torches.