Effects Of Drawing Process And Cold Deformation On Microstructure And Properties Of AZ31 Magnesium Alloy

Magnesium alloys have low density and good physical and chemical properties,and are widely used in auto parts,civil appliances,biomedicine and other fields.Magnesium alloy wire has a good application prospect in welding and cables.In this paper,AZ31 magnesium alloy wire with a diameter of(37)3.0 mm is used as the initial material,and several cold drawing experiments are carried out to improve the drawing process.The deformation and annealing heat treatment in the drawing process are beneficial to the metal materials to obtain better properties.In this paper,the drawing process is improved,and better process parameters are obtained by testing the microstructure,hardness and tensile properties.In this paper,experiments with different cumulative deformations are also carried out,and the cumulative deformations are selected as 30%,20%,and 10%,respectively.In this process,optical microscope(OM),electron backscatter diffraction(EBSD),Vickers hardness and tensile test at room temperature were used to study the effect of cumulative deformation on the microstructure and properties of wires.The study found that the metallographic structure and texture type of the wire with an average cumulative deformation of 10% are different from those with an average cumulative deformation of 30% and 20%.The grain refinement is obvious in the filaments with cumulative cold deformation of 30% and 20%,and the average grain size is reduced,the proportion of large angle grain boundary is reduced,the average grain boundary angle is reduced,and the texture type is <10(?)0>∥drawing direction.The grain size slightly reduced in the filaments with cumulative cold deformation of10%,the average grain size decreases,the proportion of large angle grain boundary increases,the average grain boundary angle increases,and the texture type is mainly in the <11(?)0>∥drawing direction.This is due to the fact that within a certain range of deformation,the more fully recrystallized,the stronger the recrystallized texture<11(?)0>.The wire with 10% deformation has more annealing times,so the recrystallization is fully carried out,which shows the simplification of the <11(?)0>orientation texture;while the wire with 20% and 30% deformation has fewer annealing times and recrystallization Inadequate progress,manifested as <10(?)0> texture.The study found that the different average cumulative deformation has a great influence on the wire properties.The change trend of the properties of the wire with an average cumulative deformation of 10% is different from that of the wire with an average cumulative deformation of 30% and 20%.With the increase of the deformation amount,the tensile strength of the wire with the cumulative deformation amount of 30% and 20% increases,the elongation rate decreases,and the hardness increases,and the wire with the cumulative deformation amount of 30% has higher strength;the tensile strength and hardness with the cumulative deformation amount of10% increase first and then decrease,and the elongation first decreases and then increases.According to the observation of the microstructure of the wire and the test results of the macroscopic mechanical properties,it is concluded that: in order to improve the strength of the wire through cold drawing to refine the grains,the cumulative deformation should reach more than 20%,and the greater the cumulative deformation,the higher of the hardness of the wire;the grains in the wire with the cumulative deformation of 10% will grow abnormally,which is not conducive to the improvement of the performance of the wire.