Análise comparativa da resistência ao cisalhamento das ligas de alumínio 3104-H34 e 5052-H32

Abstract

The shear tests are extensively employed to characterize the behavior of metal sheets sub jected to forming processes. This characterization aims primarily to establish processing conditions that allow for significant deformations without inducing plastic instability. In this study, a comparative analysis of the shear behavior under tension of the 5052-H32 and 3104-H34 aluminum alloys is conducted, considering the effect of anisotropy generated by prior sheet rolling. These alloys, which have similar mechanical strength but distinct chemi cal compositions, undergo production processes through mechanical forming under similar conditions. To perform this characterization, this study adopted the shear test method un der tension proposed by Miyauchi, based on ASTM guidelines. To complement the shear test results, both materials underwent microstructural analysis using scanning electron mi croscopy and X-ray diffraction techniques. The microstructural analysis results reveal that the 5052-H32 alloy consists of Al3Fe and Al3Mg2 intermetallic particles, while the 3104-H34 alloy shows precipitates of Al12(Fe,Mn)3Si and Al6(Fe,Mn). In both cases, these elements are randomly dispersed within an aluminum matrix (α-Al). Based on the characterization results of the shear behavior under tension, it is observed that the 5052-H32 alloy tends to yield at a lower yield stress when subjected to shear while being pulled in the 45° direction relative to its rolling direction, exhibiting greater deformation before fracture in the 45° and 60° directions. The shear fracture of this alloy will occur under similar shear stress limit values in all loading directions. On the other hand, the 3104-H34 alloy yields and fractu res under shear loading conditions in tension, maintaining identical yield stress and shear stress limit regardless of the deformation direction. However, the pre-fracture deformation will be greater when subjected to the 45° direction relative to the rolling direction.