2005 Volume 45 Issue 2 Pages 192-198
The present study focused on the evaluation of the interfacial heat transfer coefficient as a function of the surface temperature of the casting material at the interface. The casting experiments of aluminum into a cylindrical copper mold were conducted. The thermal history during the experiment was used to solve the inverse heat conduction problem. The effects of coating and superheat on the interfacial heat transfer coefficient in the liquid state, during the solidification, and in the solid state were comparatively discussed. The interfacial heat transfer coefficient was categorized into three regimes according to the phase of the casting materials. In the liquid state, the interfacial heat transfer coefficient is affected by the roughness of the mold, the wettability of the casting on the mold surface, and the physical properties of the coating layer. At the initial stage of solidification, it drops to a certain value due to the abrupt surface deformation of the casting. After then it reduces again due to contraction of the casting. In the solid state it depends only upon the thermal conductivity and the thickness of the air gap.
