The development of methods for obtaining hightensile elongation in aluminum alloys is of great importance forthe practical forming of near-net-shape parts. Currentsuperplastic aluminum alloys are limited in use by high materialcosts. The utilization of solute-drag creep processes, theapproach used in this study, to obtain enhanced tensile ductility inaluminum alloys has lead to tensile elongations of up to 325% insimple, binary Al-Mg alloys with coarse grain sizes. This methodhas the advantage of lowering processing costs in comparisonwith superplastic alloys because a fine grain size is not necessary.Whereas superplastic alloys typically have a strain-rate sensitivityofm = 0.5, the enhanced ductility Al-Mg alloys typically exhibitm = 0.3 where maximum ductility is observed. Although a strain-rate sensitivity of m = 0.5 can lead to elongations of over 1000%(superplastic materials) a value of m = 0.3 is shownexperimentally to be sufficient for obtaining elongations of150% to a maximum observed of 325%. Enhanced ductility isalso affected strongly by ternary alloying additions, such as Mn,for which a preliminary understanding is pursued.
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