Control of the yield plateau in the tensile stress—strain diagram in the course of roller straightening of aluminum—magnesium rolling products
摘要
It is indicated that a problem of nonuniform deformation, including the formation of scallops, arises in the course of sheet stamping of aluminum alloys. The presence of a tooth or a yield plateau in the tensile diagram stress-strain of the metal exerts a negative effect on the analyzed process. We formulate the problem of decreasing the yield plateau of an aluminum alloy containing 5% magnesium with the help of roller straightening. As a result of experimental investigations, we determine the tensile stress-strain diagrams of the metal for various processing conditions. It is shown that the yield plateau can be made four times smaller for the studied alloy. This enables us to get the level of practical significance of our investigations in the field of sheet stamping, where the shape and length of the yield plateau affect the possibility of localization of strains and, hence, the formation of defects. We also mention the manifestation of the Portevin-Le-Chatelier effect whose intensity decreases as a result of application of the straightening operation.