Studies On Hot Deformation Behaviors Of High-strength And High-conductivity Cu-Cr-Zr Alloy

Cu-Cr-Zr alloy is a kind of age-hardening alloy, which has high strength,electrical and thermal conductivity. Because of their excellent physical properties andcomprehensive mechanical properties their is widely used in industrial departmentssuch as electronic, mechanical, and national defense etc. In this thesis we have studiedhot deformation behaviors of aged and cold rolled+aged Cu-Cr-Zr alloy, which werestudied with a Gleeble-3500thermal simulation test machine.Analysis deformationbehaviors of two kinds Cu-Cr-Zr alloy with different thermal deformation parameters,The deformation microstructure of Cu-Cr-Zr alloy during hot deformation were studiedsystematically by optical microscopy and transmitted electron microscopy.Through the heat simulation experiment of Cu-Cr-Zr alloy with two states, theflow curves at various temperatures from room temperature to700℃and strain ratesfrom0.0001s-1to0.1s-1were obtained.Results show that Cu-Cr-Zr alloy of thesensitive alloy to the deformation temperature and strain rate. With the deformationtemperature increases and strain rate decreases, the flow stress and peak stress weredecreases. The result show that the flow stress and hardness of cold rolled+aged stateis lower than aged state at temperature of300to500℃, the flow stress and hardness ofcold rolled+aged state is higher than aged state at temperature of500to700℃.According to the true stress-strain curves of two states, the peak stress underdifferent strain rate and deformation temperature were established, the deformationbehaviors of Cu-Cr-Zr alloy could be represented by hyperbolic sine equation, and calculated the hot deformation activation energy of aged alloy is311.43KJ/mol andcold rolled+aged alloy is225.20KJ/mol. The constitutive equation for flow stress oftwo states Cu-Cr-Zr alloy were described.The microstructure evolution of two states Cu-Cr-Zr alloy during hot deformationwere analyzed. The results indicated that with the deformation temperature increasesand strain rate decreases, the deformation degree increases, Comparison analysis theprecipitated phases of two states Cu-Cr-Zr alloy during hot deformation. The resultsindicate that with the deformation temperature increases, the precipitated phase grewup. The size of precipitated phase of cold rolled+aged state is greater than aged state attemperature of300to500℃, the size of precipitated phase of cold rolled+aged state isless than aged state at temperature of500to700℃.