| Due to its low density,high specific strength and recyclability,magnesium alloy is widely used in aerospace,automobile and so on.Magnesium alloys are also widely used in welding,In the welding process welding wire is extremely important filler metal,so the preparation of magnesium alloy wire technology research is particularly important.Drawing is an ideal forming process for the preparation of magnesium alloy wire.However,there are a lot of deficiencies in the process of preparing the wire by the commonly used cold drawing process.Due to the poor plasticity of magnesium alloy at room temperature,cracks and broken wires are easily generated in the cold drawing process,and the deformation of the magnesium alloy is small and the number of drawing is small and the annealing frequently takes place,resulting in low production efficiency.According to the broad application prospect of magnesium alloy wire and domestic current research situation,we develop a hot drawing process for AZ61 magnesium alloy wire.we mainly study the influence of single-pass drawing process on the Microstructures and properties of AZ61 magnesium alloy wire during hot drawing and the regularity of Microstructures and properties of wire during multi-pass continuous hot drawing.Our purpose is to develop AZ61 magnesium alloy wire multi pass continuous drawing process,to improve the welding production efficiency,to reduce production costs,to provide technical support for AZ61 magnesium alloy welding wire production.The main contents of this paper are as follows:(1)The effect of singlepass hot drawing process parameters on Microstructures and properties of AZ61 magnesium alloy wire and finding the factors that affect the ultimate cumulative deformation of wire.(2)Variation of Microstructures and properties of AZ61 magnesium alloy wire during multi-pass continuous hot drawing.The main conclusions are as follows:(1)During single-pass hot drawing of AZ61 magnesium alloy wire,the magnesium alloy wire will be obviously broken if the drawing temperature is too high or the deformation of the pass is too large.(2)In the AZ61 magnesium alloy wire single-pass hot drawing process,As the amount of deformation of the pass increased from 10%to 25%,the strength and hardness of the magnesium alloy wire gradually increased,and the elongation decreased.When the amount of deformation is constant,as the temperature increases from 25? to 400?,the strength and hardness of the magnesium alloy wire gradually decrease,and the elongation increases gradually.(3)In the range of drawing speed parameters(5m/min to 30m/min)in this experiment,the change of drawing speed has no obvious effect on the structure and properties of the wire.(4)Compared with air cooling,After drawing,the wire is treated by water cooling.The number of twins increase,The degree of grain crushing increases,At the same time,the strength and hardness of the wire increased while the elongation decreased.(5)In the process of multi pass continuous hot drawing,when the drawing temperature is certainat at 200 ?,The average single-pass deformation(11.02%to 20%)had no significant effect on the ultimate cumulative deformation(about 36%).When the average amount of pass deformation is 10%,as the drawing temperature increased from 25? to 300?,the ultimate cumulative deformation increased from 24.02%to 48.64%.(6)According to the study of single pass hot drawing process variables,combined with the influencing factors of the ultimate pass deformation during multi-pass continuous hot drawing,we formulate a multi pass continuous hot drawing experiment scheme.We success AZ61 magnesium alloy ?6.00mm round bar after 26 hot drawn to ?0.72mm AZ61 magnesium alloy wire.The drawing temperature is 250?,the total deformation amount is 98.56%.During the period,only 4 intermediate annealing is carried out.The tensile strength of ?0.72mm wire finished by the program reached 289.86Mpa,the dimension deviation is small,the surface quality is good,and it conforms to the national standard. |
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