Study On The Relationship Between AZ80 Magnesium Alloy Hydrostatic Extrusion Tissue And Performance

Magnesium alloys can improve mechanical properties by plastic deformation,but also accompany strength or plastic loss.The majority of research scholars have been committed to continually exploring new methods for improving strength and plastics.In recent years,with the proposal of heterogeneous materials,we provide new ideas to improve the comprehensive mechanics performance of materials.Heterogeneous tissue includes a variety of forms,and its strong toughen is mainly coordinated by soft and hard phase,induces geometric essential dislocation and in the interface plug,thereby,back stress is generated in the soft phase,the hard phase is active,and the two are co-enhanced under the induction of heterogeneous deformation,producing additional processing hardening,so that the material increases the strength while increasing strength.In this paper,a thick-combined heterogeneous magnesium alloy was prepared by the hydrostatic extrusion process,and the evolution of tissue evolution and its mechanical behavior during the deformation of the hydrostatic extrusion magnesium,and the deformation mechanism of the typical heterogeneous magnesium alloy after the process is optimized.research.At the same time,the hot rolling process was combined on the basis of the static liquid extrusion process,and the microstructure and mechanical properties of the superimposed material were studied,and the intrinsic connection between microstructure and mechanical properties were established.The main research contents and conclusions of this paper are as follows::（1）By hydrostatic extrusion,the alternate distribution of coarse and ultrafine grains could be effectively prepared.The hydrostatic extrusion mainly relying on stress domain to activate deformation twins and macro and microscopic shear belt refined grains,where high strain in the macro shear belt can cause high heat energy to cause complete recrystallization,thereby forming ultrafine crystal belt（or zone）.The hydrostatic squeezing was excited in the magnesium alloy to help coordinate the strain in the C-axis direction.Two morphological nano-precipitation phases occurred in the squeezed magnesium alloy,and the phase separation in the superfine album was formed,forming an irregular second phase of the AlZn shape.（2）By optimizing the hydrostatic extrusion process,appropriately extending the insulation time is more excellent in heterogeneous tissue,the uniform elongation of 13.3%after the optimization process was optimized,and the limit tensile strength was increased to 391 MPa,and the yield strength was also improved to 330 MPa.It was found that heterogeneous induced strengthening,shear band strengthening,and precipitation strengthening mechanism by micro-characterization.（3）The coarse fine grain was used in fixed-point sampling using FIB.It was found that the thick crystal bond shape and the layer-like-shaped phase was precipitated phaseβ-Mg₁₇Al₁₂,and the substrate was kept the gerid relationship.The phase separation occursed in the ultrafine strain,forming a thick second phaseβ-Mg₁₇Al₁₂,which is equivalent to the size of the ultrafine grain.This second phase can also dissolve a small amount of Zn element,evenly distributed between superfine crystals,can hinder the slip and rotation of superfine crystals.（4）By performing the rolling post-compression of the hydrostatic extrusion material,a poor mechanical properties were obtained,and the heterogeneous tissue is the optimal performance structure in tissue design.