High-temperature deformation and enhanced ductility of friction stir processed-7010 Aluminum Alloy

In the present study the microstructural and high-temperature mechanical properties of 7010 Aluminum Alloy (AA) resulting from friction stir processing (FSP) were analyzed and compared to unprocessed material. The sheets were processed perpendicularly to the rolling direction that resulted into fine-grained microstructure having the size of about 7 mu m. The high-temperature deformation characteristics and mechanical properties of the processed material were studied using hot tensile tests at temperatures of 703, 723 and 753 K and at different strain rates in the range of 1 x 10(-2)-1 x 10(-4) s(-1). Correlation between the flow stress sigma and strain rate e and temperature. T gave an apparent stress exponent no of 5 and apparent activation energy Q(a) of 260 kJ/mol. The high value of Q(a) was attributed to the presence of threshold stress under the present experimental conditions. (C) 2010 Elsevier Ltd. All rights reserved.