Practical process of degassificatien of molton aluminium with Cl₂ gas, was investigated and the resuls obtained may be summarized as follows:
1. The greater the amount of Cl₂ gas is passed through the molten meltal per unit time is, the shorter is the total time for degassification. From these resuts, the following equation was obtained:
t=ke^-M/a
where t: the passing time of Cl₂ gas, M: the amount of Cl₂ gas passed per unit time, a & k: constant.
2. The total amount of Cl₂ gas for degassification was influenced by the amount of Cl₂ gas passed per unit time.
3. The higher the temperature of the molten metal is, the larger becomes the effect of degassification. The activation energy for degassification by Cl₂ gas treatment was about 50, 000cal/mol.
4. The more blisters are on the. sheet surface, the more are the fine fractures This result agrees with our opinion that the blister has much to do with the shrinkage cavity, which are accompanied by very small cracks during solidificaton.