Grain growth behavior of a nanostructured 5083 Al-Mg alloy

A nanostructured 5083 Al-Mg alloy powder was subjected to various thermal h eat treatments in an attempt to understand the fundamental mechanisms of re covery, recrystallization and grain growth as they apply to nanostructured materials. A low-temperature stress relaxation process associated with reor dering of the grain boundaries was found to occur at 158 degreesC. A bimoda l restructuring of the grains occurred at 307 degreesC for the unconstraine d grains and 381 degreesC for the constrained grains. An approximate activa tion energy of 5.6 kJ/mol was found for the metastable nanostructured grain s, while an approximate activation energy of 142 kJ/mol was found above the restructuring temperature.