Abstract
The correlation between compression conditions at temperatures in the range of 573–773 K with strain rate range of 0.002–2 s−1 and grain size after solution heat treatment (SHT) of 6061 aluminum alloy, was investigated. It is concluded that the grain coarsening occurred under specific Zener-Hollomon parameters of 108~2×1012 s−1. This phenomenon could be explained by crystalline orientation analysis and stored deformation energy evaluation. Small Z parameter condition could get low stored strain with fine grains which were stable during SHT. High Z parameter condition could get high stored strain, so a lot of small recrystallized grains were formed after SHT. Effect of Cr and Zr contents on the grain size of 6061 aluminum alloy was also investigated. Grains were fine when 0.34 mass%Cr or 0.17 mass%Cr and 0.14 mass%Zr were added due to pinning effects of Cr bearing dispersoids and Zr bearing dispersoids to grainboundaries.
