Al–6%Mg合金の結晶粒成長挙動

抄録

Grain growth behavior in Al–6%Mg alloy was investigated and the results were as follows. (1) The grain growth kinetics for the early stages of annealing obeyed parabolic kinetics (D/2)² − (D₀/2)²=Kt, where D is a grain size after annealing for time, t, K is a temperature-dependent rate parameter and D₀ is the grain size at time equal to zero. The apparent activation energy of the grain growth for the early stages of annealing was 1.05 eV and it was supposed that the process was diffusion controlled by Mg atoms. Equilibrium grain size was present for the later stages of annealing and the temperature dependence was observed. (2) It is supposed that the equilibrium grain size is caused by the loss of mobility due to the segregation of solute atom (Mg) on the grain boundary, and that its temperature dependence is due to the temperature dependence of the magnitude of segregation of solute atom on the grain boundary.