Preparation Of Semi-continuous Casting ER5356 Welding Wire And Joint Performance

With the rapid development of China's rail transportation,aerospace and other industries,the application scope of aluminum alloys is becoming more and more extensive,and the application volume is increasing year by year.The quality requirements for aluminum alloy welding wires are gradually increasing.At present,the domestically used aluminum alloy welding wire with a large amount of use in our country has many internal defects in the welding wire,and there is a certain gap between the domestic welding wire and foreign welding wires in mechanical properties and welding performance.In this subject,ER5356 aluminum alloy ingots containing 0.05%and 0.15%Mn were first prepared by semi-continuous casting and gravity casting methods,and then extruded into rods,drawn into wires,and tested for mechanical properties and metallographic structure.Then ER5356 aluminum alloy welding wire obtained by semi-continuous casting was used to weld 6082 and 7005 aluminum alloys respectively,and the metallographic structure observation,micro hardness test,mechanical property test,fracture scan and other tests were performed on the welded joint.This topic studies the effect of Mn element on aluminum alloy welding joints,which has important practical significance and reference value for the existing aluminum alloy welding wire production and welding.The quality of the ER5356 aluminum alloy ingot obtained by semi-continuous casting technology is better than that of the aluminum alloy ingot obtained by gravity casting method.The ingot metallographic structure of manganese content of 0.15%contains more Al-Mn phases.After the ingot is extruded,the grain boundaries disappear,and the mechanical properties of the extruded rod obtained by semi-continuous casting are better than those obtained by gravity casting.In the drawing test,as the number of drawing passes increases,the degree of smashing of the grains in the longitudinal section of the welding wire deepens,the grain boundaries of the cross-section welding wire disappear,and the fibrous structure along the drawing direction becomes deeper.The trend is even more pronounced.As the number of passes increases,the surface hardness of the wire increases.The quality of ER5356 aluminum alloy welding wire obtained by semi-continuous casting is better than that obtained by gravity casting method.In the 6082 and 7005 aluminum alloy welding tests,the quality of the welded joints obtained by the ER5356 aluminum alloy wire with a manganese content of 0.15%is better than that of the ER5356 aluminum alloy wires with a manganese content of 0.05%.Under the condition of lower welding current,there are obvious welding defects in the weld zone.As the welding current increases,the welding defects are reduced and the quality of the weld is improved.According to the two sets of mechanical properties and fracture EDS composition diagrams,it is known that Mn element can improve the metal deposition process in welding,thereby improving the welding quality.The matching coefficients of 6082 and 7005 welded joints obtained by semi-continuous casting ER5356 aluminum alloy welding wire containing 0.15%manganese can reach 0.71 and 0.64.