Study On Electromagnetic Heat Strengthening Of ZL201 Welded Joints

Aluminum Alloy due to the advantages of high strength,light weight,good corrosion resistance,no magnetism is widely used in all kinds of welding structure,and Aluminum Alloy high specific heat capacity,high thermal conductivity and linear expansion coefficient characteristics and its causes of welding prone to crack,holes and other defects in the internal components.As a new technology,the electromagnetic thermal hardening technology can not only repair the defects in the welded parts,but also improve the mechanical properties of the welded components.Because there is less research on strengthening in electromagnetic thermal internal defects Aluminum Alloy,so this paper uses the method of theoretical analysis,experiment combined with numerical simulation,the internal defects of welded joints under different welding modes of ZL201 enhanced electromagnetic heating,the main contents include the following aspects:(1)By means of fluid flow around a plane in the theory of complex potential function in fluid mechanics,the complex potential function is constructed in the electric field,establish the analysis model with hole defect theory,pulse discharge holes near the current density and temperature distribution are derived,through the example analysis solution holes near a point in the temperature change curve of pulse discharge.(2)The ZL201 welded joints were fabricated by TIG welding,and the pulse discharge experiments were carried out on the ZL-2 pulse discharge device,after discharge and discharge of the specimen has the mechanical properties,fracture morphology,EDS composition,microstructure and microhardness were analyzed,revealing the mechanism of strengthening technology of internal defects of welding joints strengthened by electromagnetic heating from the experimental point of view.(3)The preparation of FSW welding specimens of ZL201 welding joints,at different discharge voltages of electromagnetic heat strengthening test,impact toughness test,fracture analysis,metallographic analysis and hardness experiment based on non discharge and discharge specimens,studied the influence of discharge parameters and properties of ZL201 welding joint microstructure.(4)After FSW welding specimens and the numerical simulation of electromagnetic heat strengthened,established the finite element with hole defect analysis model,solving the current density,different discharge voltage of the Joule heat,the temperature field and stress field were added for further analysis of the experimental results.This paper from the theory,experiment and numerical simulation on three different welding form containing defects of ZL201 were studied to strengthen the electromagnetic heat welded joints,the results show that: the electromagnetic heat strengthening technology can improve the mechanical properties and impact toughness of welded joints,the extension of the application and development of electric magnetic heat hardening technology in welding field.