Research On Forming Process And Microstructure Properties Of ER2319 Aluminum Alloy Magnetically Controlled Arc Additive Manufacturing

Aluminum-copper alloy,as a typical light alloy material,is widely used in military industry,nuclear energy,aerospace,transportation,bridge construction,chemical industry and other modern manufacturing fields.It has a wide application prospect.However,there are some problems in the additive manufacturing process of this kind of aluminum alloy,such as component deformation,low forming precision and uneven microstructure and performance,it is easy to produce defects such as pore or cracks,which is not conducive to large-scale production and use.Therefore,it is significance to research the forming process of aluminum alloy arc additive manufacturing.This paper mainly takes ER2319 aluminum alloy as the research object.Different arc additive stacking paths are designed.Based on the optimal arc additive stacking paths,different external magnetic fields are introduced.The macroscopic morphology,microstructure and mechanical properties of arc additive component were tested and analyzed.The influence law and mechanism of stacking path and magnetic field parameters on additive component were discussed.In addition,optimize the forming quality of component and improve the microstructure and mechanical properties of arc additive component.The stacking path affects the macroscopic surface forming quality of component,which is manifested in the macroscopic morphology and surface flatness of component.Under the stacking path 4,the macroscopic morphology of component is the best,the surface flatness is the smallest,and the forming quality of component is the best.Under the four stacking paths,the microstructure is relatively complex.The microstructure is mainly composed of columnar crystal and equiaxial crystal,and the overall distribution is layered and uneven,with obvious directivity.The stacking path has an impact on the mechanical properties of the component.The strength of the component under the stacking path 4 is improved compared with other stacking paths,the tensile strength of the component is increased by 64MPa(20%),the yield strength by 45MPa(6%)compared with stacking paths 2,and the elongation of the component is 14.95%,and the hardness of the component is up to 70.24 HV.Obvious surface root cracks can be seen at stacking path 1,stacking path 2 and stacking path 3,However,there were no obvious surface root cracks under the stacking path.After introducing the external magnetic field,with the increase of excitation current and excitation frequency,the surface flatness of additive component tends to decrease first and then increase,and the macrostructure of component is optimized and then degraded.In terms of microstructure,the internal grains of additive component first is going to be fine and uniform and then thicker.In terms of mechanical properties,the strength of the component increases first and then decreases.When the excitation current is 5A,the excitation frequency is 50 Hz,the component has the smallest surface roughness and the best macroscopic morphology.The internal microstructure of the component is mostly fine and uniform equiaxed crystal,and the grain refinement is the most obvious.The tensile strength of the component reaches 420 MPa,which is increased by 38MPa(10%)compared with that of the non-magnetic field and the yield strength is 382 MPa,which is increased by 16 MPa.The elongation is 20.51% and relatively the largest,compared with the non-magnetic field,the increase is 5.56%.