Studying the Influence of Radial-Shear Rolling on Thermal Deformation Conditions of A1050 Processing

摘要

The analysis of the influence exerted by the deformation techniques on the conditions of radial-shear rolling (RSR) of commercial purity aluminum A1050 is carried out. Based on finite-element modeling (FEM), the temperature change at various feed angles and elongation in the first and last passes is obtained. The increase in feed angle slightly raises the temperature variations in the surface layer due to the increase in reduction per pass but does not significantly influence total deformation heating during the RSR process. The finishing deformation temperature can be controlled by varying a reduction ratio. In this case, it is necessary to take into account the initial temperature of heating, dimensions of rolled products obtained, and elongation per pass. The dimensions of a workpiece have a significant effect on thermal changes in the RSR process. In the last pass, when the diameters are 20-14 mm, deformation heating is almost completely compensated for by rod cooling upon contact between the environment and the tool and begins to prevail, with an increase in elongation ratio of more than 1.2. An analysis of effective strain (epsilon(eff)) at various deformation modes shows that the difference in epsilon(eff) values over the cross section of the rod decreases with an increasing feed angle. A comparison of the data with the hardness and microstructure of the rolled A1050 samples shows that epsilon(eff) has a significant impact on the change in the structure and properties to a certain value, which is confirmed by the distribution of the microhardness over the cross section of the rods. The mechanical properties of the rods correspond to the properties of commercial purity aluminum in the work-hardened state (sigma(eff) similar to 115 MPa, sigma(0.2) similar to 110 MPa, delta similar to 1%, HV similar to 40-43).