再結晶したアルミニウムの粒成長過程における結晶粒度分布の変化

Abstract

The change in the grain size distribution during grain growth has been investigated for recrystallized aluminum specimens, some of which contain a small amount of chromium. The one- and two-dimensional distributions were measured experimentally. Further, the grain diameter distribution, which is one of the three-dimensional grain size distributions corresponding directly to grain growth, was estimated by the method suggested in the previous paper using the values obtained for the one-dimensional distribution. This method was based on an assumption of the log-normal distribution of the grain diameter (the equivalent volume diameter) D; the distribution of this grain diameter was clearly defined by the geometric mean grain diameter Dg and the standard deviation of lnD, lnσg. As a result, the change in the grain diameter distribution during grain growth was different from that in the one- or the two-dimensional distribution. The value of Dg of pure Al increased remarkably during the annealing in this experiment, while that of specimens containing Cr varied similary with annealing time and then it became unchanged or slightly decreased. The standard deviation of the logarithm of the grain diameter, lnσg decreased with the increase in Dg, or increased as the value of Dg stagnated or decreased slightly. The results were discussed briefly in relation to abnormal grain growth.