Investigation into the effect on superplastic behavior of two aluminum alloys produced by variations of thermomechanical processing parameters was conducted. The alloys in this study are Al-10Mg-0.1Zr (weight percent) and 2090, which is Al-2.56Cu-2.03Li-0.12Zr (weight percent). Determination of the existence of an optimum balance between deformation and recovery for the Al-10Mg-0.1Zr alloy was accomplished by extending the annealing interval to 60 minutes during warm rolling at 300 C. The optimum balance is a 30 minute annealing interval between rolling passes. Processing of Al-10Mg-0.1Zr with a rolling temperature lower than the annealing temperature produced ductilities which are less than those obtained by utilization of the optimum process. The extension of annealing intervals in the processing of 2090 resulted in increased superplastic response when compared with results obtained employing shorter annealing intervals. By application of a two-temperature process which incorporates rolling at a lower temperature than the annealing temperature, the determination has been made that enhanced ductility results however, the annealing interval of 14 minutes should be extended.
Naval Postgraduate School (U.S.)
Naval Postgraduate School
M.S. in Mechanical Engineering
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