Effect of symmetric and asymmetric rolling on the mechanical properties of AA5182. (15th June 2016)

• Record Type: Journal Article
• Authors: Bintu, A.; Vincze, G.; Picu, R.C.; Lopes, A.B.
• Is Part Of: Materials & design. Volume 100(2016)
• Page Start: 151
• Page End: 156
• Publication Date: 2016-06-15
• Subjects: Aluminum alloys -- Asymmetric rolling -- Severe plastic deformation -- Strain rate sensitivity -- Heat treatment -- Microstructure; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2016.03.123
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: In this work we study the response of AA5182 to rolling, with emphasis on the effect of severe plastic deformation followed by heat treatment on the strain rate sensitivity of the material. Three rolling techniques are compared namely symmetric rolling, continuous and reversed asymmetric rolling and the subsequent heat treatment is performed at 195 °C for times ranging from 30 to 120 mins. The strain rate sensitivity is unaffected by rolling for rolling reductions smaller than 50%. For larger reductions it increases gradually, but remains negative even for reductions as high as 90%. The schedule of the heat treatment makes a difference only for samples with 90% reduction. In these cases the yield stress of symmetrically rolled samples decreases with increasing annealing time, while that of asymmetrically rolled samples increases under the same conditions. Microstructural observations indicate that the grain size decreases continuously, being more pronounced for reductions larger than 50%. Rolling introduces low angle grain boundaries at reductions below 50%, which transform in high angle boundaries at higher reductions. Nanoscale grains are obtained with all rolling methods at 90% reduction. Several mechanisms that may cause the increase of the strain rate sensitivity parameter for reductions larger than 50% are discussed. Graphical abstract: Highlights: Experimental evaluation of strain rate sensitivity of aluminum alloys processed by rolling (SR and ASR) and annealing The negative strain rate sensitivity parameter m increases for rolling reduction higher then 50% Inverse effect of annealing in observed for 90% reduction in asymmetric reverse rolling Several mechanisms which may lead to the observed increase of m are discussed