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.7085 Aluminum Alloy During Hot Deformation Behavior And Processing Map

Posted on:2012-06-14Degree:MasterType:Thesis
Country:ChinaCandidate:X H ChenFull Text:PDF
GTID:2191330335490912Subject:Materials science
Abstract/Summary:PDF Full Text Request
7085 aluminum alloy is a new type of aluminum alloy which has high comprehensive properties of high strength, fracture toughness, high harden ability and abrasion resistance.It has an important transmission applications in fields of aerospace industry, national defense and military industry. The heat process technology had been studied for aircraft aluminum parts of 7085 aluminum alloy in this paper. The behavior of the flow stress and evolution of deformation microstructure of 7085 aluminum alloy during hot deformation were studied systematically with aids of OM and TEM conducted on the Gleeble-1500 thermal simulation machine. The processing map of 7085 aluminum alloy was established, which based on dynamic materials model. And the processing properties of 7085 aluminum alloy were analyzed in detail. The main conclusions are as follows:(1) This relationship between the flow stress and parameter of heat deformation were studied.The experimental results indicate that the flow stress and peak stress corresponding strain decrease with increasing deformation temperature and the flow stress decrease with increasing strain rate. This relationship among peak stress and deformation temperature and strain rate and dynamic recrystallization model were described by the linear regression method.(2) The microstructure evolution of 7085 aluminum alloy during hot deformation is revealed. The results indicate that both increasing deformation temperature and decreasing strain rate are helped to the dynamic recrystallization phenomenon. At the same deformation temperature and strain rate, the recrystallization volume percent increases with the strain increasing. The dynamic recrystallization model was described with the experimental results of the 7085 aluminum alloy after deformation.(3) After analyzing the processing map of 7085 aluminum alloy, the results demonstrate that the strain has little influence on processing map of 7085 aluminum alloy.The area with deformation temperature (340℃~450℃) and strain rate(0.0001 s-1~1 s-1)is processing safety area for hot deformation of the 7085 aluminum alloy. The flow instability region and adiabatic shear banding occur in the temperature range from 300℃to 340℃and strain rate range from 0.01 s-1to 1 s-1.The structure of adiabatic shear banding is violently elongated grain. The potential processing dangerous area is in the temperature range from 300℃to 340℃and strain rate range from 0.0001 s-1 to 0.01 s-1.
Keywords/Search Tags:7085 aluminum alloy, heat deformation parameters, flow stress, constitutive equations, microstructure evolution, dynamic recrystallization mathematical model, processing map
PDF Full Text Request
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