Abstract
Effect of grain size on the surface roughening of deformed aluminium sheet was described in the Report (I), but its effects on the other propeties of the metal are also important.
In this paper, the efect of grain size on the elongation and Erichsen value is investigated, and, for the study on the grain size control, the effects of impurities, such as Fe, Si, to the grain growth of aluminium are also examined.
The findings are as follows:
1. With increase in grain size, elongation decreases hyperbolically.
2. Erichsen value moves in proportion to the change in elongation, but in inverse proportion to the coefficient of width contraction.
3. The higher is the purity of aluminium, the more remarkable is the growth rate of grains under a certain annealing time and temperature. This phenomenon is particularly remarkable, when the purity is more than 99.7%.
4. Fe, as an impurity in aluminium gives remarkable obstructive effect to the grain growth under a certain annealing time and temperature, while Si does not so remarkable.
