Thermal behavior of aluminum-magnesium alloy (JIS AC7A) casting pots were tested by measuring temperature change of the pots heated by town gas heater. Temperatures were measured by I.C. thermocouples fixed to several points.
As for the empty pots heated by constant flow of town gas, it was found that the temperature (t) of each point of the bottoms of the tested pots increased in the form of t=t _max {1-exp (-kτ)}, where t_max is maximum temperature of measured points at steady state, k is a constant defined by experimental conditions, and τ is time for heating.
When the gas flow was full-opened, the temperature at the bottom center of the pot rose up to about 400°C in 4 min after heating started. At temperature around 600 C, swelling of aluminum alloy was observed on the bottom center of the nontreated pot, whereas no swelling was observed on that of the anodized pot.
In the case of heating of pots filled with water, the temperature of pots reached a maximum value around 105°C before boiling the bulk of water.