Study on the aluminium (alloy) sheet ingot (2nd Report)
Annual ring-like structure in the grain
1961 Volume 11 Issue 2 Pages 89-95
Details
1961 Volume 11 Issue 2 Pages 89-95
This is to report of a study on the annual-ring like structure which appears in slab of commercially pure aluminium produced by the semi-continuous casting process. This structure is seen in the central part of the slab but not in the outer part. It is recognized through interferrometer that the part of rings is dented by etching. This structure disappears when the slab is heated at 500°C for more than 48 hours or rolled down to 68.8% or more reduction. It is considered, therefore, that this does not give any influence to the rolling work in practice. On the other hand, the three dimentional variation of this part has been observed by means of repeating the polishing. From the above-mentioned study, it is considered that this annual-ring structure is formed by the nonuniformity of dcnsity of the solid solution on the condition of formation of which has been further studied.
