Microstructural evolution and enhanced properties by multi-directional forging of 6201 aluminum alloy

In this work, the microstructure evolution and mechanical properties of 6201 aluminum alloy during multi-directional forging (MDF) and solution-aging were systematically studied. In the MDF process, the deformation of 6201 aluminum alloy was not uniform, and the increase of forging passes can effectively improve the inhomogeneity. With the increase of forging passes, the alloy changed from dynamic recovery to dynamic recrystallization, the grains in the center were refined obviously, and the anisotropy of microstructure was eliminated. After 9 passes of MDF followed by the solution-aging, the re-dissolution and re-precipitation behavior of the second phases significantly improved the mechanical properties of the alloy. The tensile strength, yield strength, elongation and conductivity of the alloy were 257 MPa, 139 MPa, 16.1%, 51.6% IACS, respectively, 55.8%, 73.8%, 3.4% and 10.5% higher than that of the as-cast alloy. At the same time, the average grain size of the alloy was decreased to 133 μm, 50.9% lower than that of the initial one.