Investigation Of The Organization,Properties And Thermal Deformation Behavior Of Mg-Cu Binary Alloy

Magnesium alloy is widely used in aerospace,automotive,3C and other fields due to its excellent characteristics such as low density,high strength and easy recycling.However,its poor corrosion resistance increases the cost and risk of applications in the above fields.However,easy corrosion is a performance advantage in some other fields,for example,in the field of unconventional energy extraction,magnesium alloy can also play the easy dissolution sometimes,used to prepare temporary plugging tools.mg-Cu binary alloy as a non-commercial magnesium alloy,has a lower economic cost than other alloy system magnesium alloy,has great potential for application.In this study,the Mg-x Cu（x=2,10,20）alloy was taken as the object of study,and its microstructure and properties were observed and analyzed;isothermal compression simulation experiments were conducted on the as-cast Mg-10Cu alloy,relying on the real rheological stress-strain curve and constructing the sinusoidal intrinsic structure model;with the dynamic material model as the theoretical guide,the power dissipation diagram and thermal processing diagram of Mg-10Cu alloy were drawn to determine the best processing process range,and the following main conclusions were drawn:The Mg-x Cu（x=2,10,20）alloy consists of Mg₂Cu and Mg Cu₂intermediate phases in addition to theα-Mg matrix.The corrosion properties test results indicated that the corrosion rate of Mg-10Cu alloy is moderately stable and the comprehensive mechanical properties,which meet the development criteria of low-cost fracture temporary plugging soluble tools,therefore,Mg-10Cu alloy was selected for subsequent experimental analysis.The rheological stress-strain curve of Mg-10Cu magnesium alloy during isothermal hot compression simulation shows a typical characteristic of single broad peak.When the softening effect has a gap with the work hardening,the flow stress starts to decrease.The curve tends to level off when the effects of both actions maintain equilibrium and stability,after the formation of steady-state stresses.By calculating the correlation coefficient（R）,the average absolute relative error（AARE）and the root mean square error（RMSE）,the results show that the construction of an intrinsic relationship model considering the effect of strain can accurately describe the rheological behavior of Mg-10Cu magnesium alloy in the thermoplastic deformation stage.The thermal processing diagram reveals a similarity in the range of stable processing parameters.Combining with the actual production factors,the best hot working process parameters of Mg-10Cu magnesium alloy were derived:deformation temperature of 680K±10K and strain rate of 0.01s^-1.The dynamic recrystallization softening region of Mg-10Cu alloy during hot compression was mainly reflected in the range of deformation temperature of 680K±10K and strain rate of 0.01-0.1s^-1.Linear regression analysis of the real stress-strain curve obtained by isothermal hot compression test,a linear regression analysis was performed to derive the critical conditions for dynamic recrystallization of Mg-10Cu magnesium alloy,and a DRX kinetic model and a DRX grain size model for Mg-10Cu alloy were constructed.