Research On The Characteristics And Technology Application Of ECAP-processed Magnesium Alloy

So far,the magnesium alloys are widely used in the automotive and telecommunications industry and other fields due to their good machinability,fatigue resistance,corrosion resistance and other advantages.After entering the 21 st century,along with the further development of science and technology,all countries put forward higher requirements for the performance of metallic materials.People begin to discuss the techniques and methods to improve performance and the physical performance of magnesium and magnesium alloy mechanics.Equal channel angular extrusion(Equal Channel Angular Pressing,ECAP)technique is a kind of severe plastic deformation process which can produce bulk ultra fine-grained materials by simple shear.This paper takes the processing of magnesium alloy as the starting point to the equal channel angular extrusion,studies the change of the microstructure of magnesium alloy after ECAP,expounds the change rule of the minimum pressure of ECAP,designs equal channel angular extrusion die and special equipment for the preparation of magnesium alloy,provides a new way for the application of magnesium alloys,and achieves some research results.Firstly,through the establishment of ECAP process of material flow model,it was concluded that material strain equation;then used the calculation formula of minimum extrusion pressure of ECAP to solve the minimum pressure under different conditions;finally,through the DEFORM-3D software to finite element the simulation of the process of equal channel angular extrusion,checked the minimum of equal channel angular extrusion pressure calculation formula,amd got the change rule of the minimum pressure.Secondly,this paper designed and developed the equal channel angular extrusion die and special equipment for the preparation of magnesium alloy,and checked the strength of its important components.Thirdly,through the DEFORM-3D software to analysis the distribution of the equivalent strain distribution and stress analysis of the equivalent sample after extrusion,it was concluded that the phenomenon of stress concentration occurred easily in the die passage corner;at the ends of the specimen strain is smaller,and the middle part of the specimen strain is larger.Fourthly,through the ECAP analysis of the experimental results,obtained the extrusion process parameters influence on the surface morphology of the samples after extrusion;microstructure after extrusion samples ECAP extrusion processing of grain size than the untreated grain size specimens of ECAP extrusion processing was refined,and along with the extrusion times increasing,the grain size also decreased.In this paper the method of combining theory with experiment,expounded the influence of extrusion process parameters on ECAP,studied the influence of ECAP on microstructure of magnesium alloy,got the change rule of the minimum pressure,designed and developed equal channel angular extrusion die and special equipment for the preparation of magnesium alloy,and established a solid foundation for the realization of ECAP engineering.