The Effect Of Annealing Process On Microstructure And Mechanical Properties Of AZ31 Magnesium Alloy Wire

Magnesium and its alloys have a close-packed hexagonal crystal structure with low deformation coordination ability at room temperature.The development of new advanced heat treatment manufacturing technology for wrought magnesium alloys to improve the plasticity of magnesium alloys is the key to improving the cost performance and expanding applications of magnesium alloys.In this paper,the AZ31 magnesium alloy wire is firstly annealed and heat treated to uniformly structure and increase the recrystallized grains of the material.Using metallographic microscope(OM)and electron backscatter diffraction(EBSD),the annealing process of AZ31 magnesium alloy is studied.The evolution of microstructure and textures,the wire of different organizational states is stretched at room temperature to test their mechanical properties.The AZ31 magnesium alloy wire with a diameter of ?1.0mm is subjected to annealing heat treatment to increase the size of the crystal grains from 6.9?m to about 10?m,40?m,70?m,and 100?m.Analyze the influence law of annealing process on alloy microstructure,grain size,hardness,texture and mechanical properties.As the heat treatment temperature increases,the time increases,the more uniform the structure is,the larger the grain size.After annealing,the < 11(?)0 > silk texture changes to < 10(?)0 > silk texture,indicating that the annealed AZ31 magnesium alloy wire texture < 10(?)0 > has higher energy than the initial texture< 11(?)0 >;and < 10(?)0 >texture strength increases continuously with the increase of annealing temperature.Using the WDW-30 M computer-controlled electronic universal material testing machine,annealed AZ31 magnesium alloy wire was stretched at a speed of1mm/min at room temperature to test the annealed AZ31 magnesium alloy and the original AZ31 under the same diameter and different grain sizes.For the tensile mechanical properties of magnesium alloy filaments,the structure and texture changes and cracks are noted under different tensile deformations(5%,10%,15%).As the amount of deformation increases,the silky texture changes from < 11(?)0 > and< 10(?)0 > to < 10(?)0 > silky texture.The test results represent that the tensile strength of the initial wire is greater than of the annealed wire.As the grain size of the wire decreases,its tensile strength and yield strength both showed an upward trend,and the elongation increases.