Process Optimization And Numerical Simulation Study On Wire Arc Additive Manufacturing Of 5356 Aluminum Alloy

Due to the advantages of light weight,good corrosion resistance and easy processing,the demand of aluminum alloy in various fields of manufacturing industry is increasing gradually.However,the traditional forging and casting die forming method has gradually failed to meet the forming demand of parts with increasingly complex structure.Compared with other metal additive manufacturing technologies,wire arc additive manufacture(WAAM)uses the energy generated by arc as the heat source,which has certain advantages in material utilization,forming size,cost and efficiency.However,there are still some problems in forming aluminum alloy with arc additive manufacturing technology,such as high technical difficulty,complex process parameters and low forming accuracy.In this paper,based on the polar coordinate three-dimensional forming platform,the dimensional accuracy and quality of single-layer,multi-layer and multiweld forming parts in 5356 aluminum alloy waam under different process parameters are studied,and the temperature field,stress field and deformation of single-channel multilayer forming are numerically simulated by using the finite element software.Firstly,the basic process of MIG(Melt Inert Gas)welding of 5356 aluminum alloy on the 6061 aluminum alloy plate with the thickness of 8 mm was studied,and the influence of process parameters on the forming size and quality of single layer was analyzed.The results showed that the main order of influencing factors on weld bead width and reinforcement was welding speed > welding current > arc voltage.The results of the orthogonal test were optimized by the experimental analysis method,and the optimal process parameters were obtained: welding current 120 A,welding speed 4mm /s,arc voltage 19V;the surface quality of the formed weld bead was good without obvious defects.Secondly,a single pass and multi-layer welding model of 10 passes of 5356 aluminum alloy is established,and the welding temperature field,stress field and deformation are simulated by simufact.welding.The results show that a certain cooling time between layers can reduce the collapse risk of components under the cumulative effect of heat during multi-layer forming;by analyzing the evolution law of stress field and deformation,the main areas of residual stress and deformation distribution are obtained.Then a multilayer experiment of 5356 aluminum alloy was carried out on a 10 mm thick 6061 aluminum alloy plate.It is found that the use of alternative forming path can effectively improve the collapse and bulge of single pass multi-layer forming caused by the accumulation of arc starting and arc stopping defects in the experiment,and the change rule of weld bead size and surface morphology under different cooling time between layers are compared.The results show that when the waiting time between layers is 60 s,the size and surface flatness of components can be better controlled.Finally,the ideal lap model between adjacent weld beads of aluminum alloy is established,and the optimal lap distance under certain process parameters is calculated.Different groups of control experiments are designed to test the correctness of the model results.The results show that the surface flatness of the single-layer and multi-channel parts is better,and the optimal lap distance is 4.45 mm.