The Temperature Distribution Research of Foaming Gypsum Mold in the Fabrication and Pouring Process

This paper describes study of temperature variation in the gelling and hardening, thermal baking and pouring stage of foaming gypsum mold. The temperature difference curve in the gelling and hardening process shows an rapid decline, tending to the placid downward eventually after a clipping rise. During the thermal baking stage, owing to the low heat conduction coefficient of the foaming gypsum mold, the actual temperature of each thermocouple lags behind the craft temperature, lag degree increases gradually with the extension of baking temperature and holding time. At the initial period of pouring process for molten aluminum, the temperature of center position in the mold increases fast by absorbing lots of heat in the solidification process, whereas, slower temperature rising curve occurs in the edge and intersection position. Coupled with the ongoing of air convection heat transfer, resulting in a continuous falling of temperature, therefore the temperature difference curve of each point inside the mold shows a successive upward trend with the solidification process of molten aluminum alloy.