Effect of wall angle on Al 3003 strain hardening for parts formed by computer numerical control incremental forming

摘要

The change in material properties for annealed Al 3003 after computer numerical control (CNC) incremental forming was studied through a series of tensile tests. Specific shapes were designed with wall angles of 20-60°, in 10° increments, to allow for removal of flat specimens of adequate size. A relationship was found, with plots of stress-strain curves, showing an increase in yield and necking stress for increasing wall angle. Empirical equations proposed by both Hollomon and Voce were applied to the data, showing the usefulness of each method for Al 3003 formed to large strains. Strain data were used to offset the stress-strain curves, and show a tendency to follow an overall curve. A log plot of these offset curves resulted in a straight line, and therefore a Hollomon equation was determined for Al 3003 over the full range of working strain.