Enhancement of mechanical forming properties related in formability for AA2024-T3 sheet using shot peening process

This research aims to improve the formability of aluminum alloy AA2024-T3 sheets, along with their surface characteristics and mechanical forming properties, by employing the shot peening (SP) process under optimized process parameters. These parameters include a nozzle distance of 150 and 200 mm and a peening duration of 3 and 10 seconds, all while maintaining a constant pressure of 0.35 MPa using silica peening media with a diameter of 100 μm. After SP process tests, the obtained mechanical properties highly enhanced in the sheet formability and mechanical forming characteristics of the investigated peened sheets, anisotropy coefficients, yield and ultimate tensile strengths, and uniform elongations, all of which indicated significant increases. Apparently, the testing results confirmed the improved peened sheet formability, including surface hardness and roughness, residual compressive stress, and Full Width at Half Maximum (FWHM) values from the X-ray diffraction (XRD) tester, which were exactly indicated in the reasonably improved conditions. To verify an improvement in formability under different stress states, biaxial drawing and hole expansion tests were conducted on both peened and unpeened sheets until failure occurred. The drawing depths for the peened sheets illustrated greater formability compared to those of the un-peened sheets. It can be concluded that the shot peening process significantly enhances the mechanical forming properties of the investigated AA2024-T3 sheet, resulting in greater formability considering under biaxial loading. The most effective process parameters include a nozzle distance of 200 mm and a peening duration of 3 seconds, which yield the highest formability for sheet material. • The newly discovered on the enhancement of mechanical forming properties related to material formability and ductility by using shot peening process. • The newly observed increases in anisotropy coefficients, uniform elongations, and flow stress curves indicate significant changes on peened sheets. • The obtained higher mechanical properties improvement, yield and ultimate tensile strengths, higher and extender flow stress curve since the induced residual compressive stress on sheet surface. • The shot peening process provides better formability on sheet materials by various state of stresses.