The long-term strength of substructure-strengthened and recrystallized aluminum

1.	The long-term strength of polygonized aluminum at 100°C depends on the subgrain size and on the dislocation density within the subgrains, while that of the recrystallized metal depends on the grain size: The long-term strength of aluminum increases (at least for lives up to 1000h) with reduction in the grain or subgrain size and with increase in the density of internal dislocations.
2.	The rate of loss of strength (the tangent of the angle of slope of the long-term strength curves) decreases with increase in the grain or subgrain size of aluminum; this leads to the convergence of the long-term strength curves of metal with different subgrains (or grains) at long lives.
3.	An analogy has been found between the behavior of polygonized and recrystallized in long-term strength tests at relatively short times to failure and that in short-term tensile tests.