Multidirectional Forging Strengthening And Pitting Corrosion Behavior Of Wrought Aluminum Alloys

Wrought aluminum alloys are expected to get more and more widely used in the aerospace, transportation, military equipment, and other fields because of its low density, light quality, good ductility, and high shock absorption power. However, applications of aluminum alloys are limited because their low strength and hardness. Moreover, aluminum alloys are easy to corrosion failure when chloride ions and alkaline medium presence. With the development of science and technology, the requirements of wrought aluminum alloys with high strength, hardness, fine ductility and excellent corrosion resistance have become increasingly urgent. In this work, an UFG wrought aluminum alloy with high hardness high ductility, and excellent corrosion resistance was produced by multidirectional forging and aging.In this work, a 3004 wrought aluminum alloys were subjected to MF and aging treatment Evolution of microstructure was investigated, mechanical properties and pitting corrosion were studied in comparison with coarse-grained sample.Results of strengthening show that the mechanical properties of 3004 wrought aluminum alloys are significantly enhanced by multidirectional forging and aging. The effect of strengthening and toughening to the wrought aluminum alloys is more obvious after subjecting to MF at temperature of 130℃ and artificial aging treatment when comparing to the alloys subjected to MF at room temperature. The tensile strength, hardness and elongation of sample are 422.4 MPa,120 HBW and 11.95%, respectively. Strength and hardness are significantly enhanced due to the grain-size of samples is reduced and the accumulation of deformation multidirectional forging. The ductility is improved by reducing the residual stresses. Moreover, there are a mass of ultrafine particles distributing within the grains after aging, which help to accumulate dislocations, increase the dislocation storage capability and resist dislocation slip, and then the ductility is also enhanced.After multidirectional forging and aging, high pitting corrosion resistance can be attributed to the second phase particles broken up by multidirectional forging.