Construction Of Green Magnesium Alloy Industry Chain And Research On Electroplastic Effect

There are many high-pollution and consumption processes in the magnesium alloy industry chain.Such as,magnesium reduction process of high carbon and low yield processing of magnesium alloy in the molding processIn view of the above problems,this paper established the green industry chain of magnesium alloys and focuses on the two key links of magnesium reduction and magnesium alloy plastic forming processing.The problem of high pollution and high emission was solved by mechanized slag removal;the influence of electroplastic effect on the plastic deformation of magnesium alloys was studied and the equation of electroplastic flow stress of magnesium alloys was established.Electroplastic was used instead of traditional thermal processing.Improve the rate of plastic forming processing and yield.1.Establish a green magnesium alloy industry chain.Based on the overall analysis of the current situation of the magnesium alloy industry chain,we found the problems of production process caused by energy waste,pollution emissions and so on,and provided the methods to gradually improve and optimize the production efficiency.The results of improvement and optimization of the reduction of magnesium alloy:(1)structural optimization of the reduction furnace could solve the problems of low thermal efficiency and inadequate heat exchange;(2)the use of advanced combustion technology,could be effective to solve the problems of low thermal efficiency and excessive resource consumption,and effectively reduce the emission of polluting gases;(3)the use of clean fuels could significantly reduce emissions and extend the scope of the service life of reduction tanks;(4)the improvement the degree of mechanization and automation could greatly reduce period of the reduction cycle,improve the efficiency,and reduce the labor intensity and reduce dust flying,consequently improve the operating environment;(5)the set of waste heat recovery device could maximize energy conservation,waste residue and exhaust heat for secondary use.The improvement results of magnesium alloy processing:the use of clean energy,electroplastic processing technology instead of traditional thermal processing technology,effectively reduced the emission of greenhouse gases,and energy consumption,which could save about 30%of the processing costs.2.The AZ61 magnesium alloy was selected as the material to conduct the tensile test with different electrical parameters.The microstructure observation mechanical property tests and other methods were carried on to determine the best electrical parameters to promote the mechanical properties of magnesium alloys.The experimental results showed that when the pulse current was applied,the sample showeds a significant "neck" phenomenon,and the tensile strength of the sample slightly decreaseds,but the elongation increases significantly;the number of twins in the tissue decreased,so the electroplasticity effect promoteds dislocation movement.The EBSD analysis simplied that the non-energized samples occupied 54%of the small-angle crystals with the angle of 2 ° to 10 °,but the content of the large-angle crystals was very small.When the samples were applied the pulse current,the contents of low-angle grain boundaries at 2 ° to 10 °was reduced to 39%and the content of large-angle grain boundaries distributed over the range of 20 ° to 80 ° was significantly increased.Within the scope of the study,the best electrical parameters for improving the plasticity of AZ61 magnesium alloy are:the samples were energized for 300s;the current density was 13.89A/mm2;the frequency was 400Hz.3.Established the electroplastic flow stress equation of AZ61 magnesium alloy.The Fields-Backofen model was verified and modified according to the test results of mechanical properties at room temperature without electricity or with electricity.The fitting results showed that the flow stress equation of AZ61 magnesium alloy at room temperature was σ=804.7·∈0.4·ε0.021,by setting three sets of experiments with different stretching speeds.Then,three influencing factors of current processing time,current density and frequency were introduced and the corresponding values were obtained.The equation of electroplastic flow was obtainedσF<400 = 1495·∈0.33·ε0.168 ·exp(-0.0003·T-0.0087·J-0.0004·F)and σF≥4OO=1495·∈0.33·ε0.168 ·exp(-0.0003·T-0.0087·J-0.00014·F),the fitting accuracy reaches 98%.