The Study Of Copper Microstracture During Continuous Extrusion

In order to study the micstruction during continuous extrusion, I make the case of gleeble-1500 followed by product condition of continuous extrusion, study how deformation parameter affect flow stress and metallurgical structure, fit constitutional equation of copper by true stress-strain curve, build materials modelling of DEFORM-3D numerical simulation.; buid mathematical model of copper dynamic recrystallization; simulate thermal deformation and continuous extrusion by connecting mathematical model of copper dynamic recrystallization and DEFORM-3D. watch metallurgical structure of continuous extrusion process.1. In accordance with the requirements for the production of extrusion, the deformation temperature of hot compression experiments is 20-800℃, the deformation rate is 0.01/s-1/s, quenched immediately after deformation. The results show that :(1) with the increasing deformation temperature flow stress decrease.(2) Deformation temperature affects the microstructure clear: it dose not occurrence dynamic recrystallization at a relatively low temperature (below 300℃), and it partly occurres the dynamic recrystallization between 300℃and 400℃, when the temperature up to 600℃, it will occur complete dynamic recrystallization;(3) The deformation rate also affects the microstructure, at lower temperatures, with the increasing strain rate, the occurrence of dynamic recrystallization is greater probability2. Based on the expaiment of copper thermal deformation and the thermal simulation of dynamic recrystallization theory, put forward the true stress-strain curves and phenomenological JMA equation model of dynamic recrystallization.3. Take advantage of mathematical model of dynamic recrystallization in the finite element simulation software DEFORM-3D simulation of thermal deformation of pure copper and continuous extrusion process, the conclusion is: both the deformation temperature and deformation of the impact affect grain size; grain size in pass rolling shear zones and areas of friction remain unchanged.4. According to the copper microstructure during continuous extrusion experiment,it can be analysised that: drawed out along the distortion orientation during pass rolled zone and rolling friction shear deformation zone, the grain become cell during upset zone, it produced shear bands and substructures during sticking shear zone, the grain become fibrous and appear dynamic recrystallization during right-angle bending, the grain become complete dynamic recrystallization and form fine recrystallzation grain during expansion forming zone.