Abstract
The cracks caused by working of aluminium slab often originate in the casting cracks, so the experiment was carried out to find how these cracks could be prevented under different casting conditions. About 1 kg of aluminium was cast in an iron mould, the inner dimension of which was 200×120×16 mm. The mould was fixed with the melting crucible and they were rotated together by a driving motor to get a difinite pouring speed. The metal was poured at different casting temperature, pouring speed and temperature of mould, and after the solidification, the ingots were examined with eyes or under microscope. The results were as follows:
a) The faster the pouring speed was,the greater was the cracking of ingot at the upper parts.
(b) The higher the temperature of the mould, the less the cracking was.
(c) With pure aluminium,the ingot was apt to crack for its large grains.
(d) The lining of the mould could present the casting crack.
