Ductile fracture behavior in micro-scaled progressive forming of magnesium-lithium alloy sheet

Micro-scaled progressive sheet metal forming is a promising process for producing bulk microparts, given its advantages of high efficiency and low cost. To enhance quality efficiency, it important to have an in-depth understanding the mechanism model fracture behavior accurately. However, prediction formation in materials at micro-scale has not yet been well explored, thus current knowledge sufficient support continued development application microforming technology. This study investigated magnesium-lithium alloy sheets different grain sizes produce microparts directly from via shearing, extruding, piercing, blanking. Using Gurson–Tvergaard–Needleman (GTN) damage model, effects size factor on evolution voids were considered, shear-modified GTN was established by combining Thomason’s Lemaitre’s mechanics models. The modified could predict only ductile dominated tension under high-stress triaxiality micro-scale, but also controlled shear deformation low-stress triaxiality. simulated using which verified experimentation simulation. Comparisons experiments simulations revealed defects behaviors during forming. results show that stress mainly concentrated edge irregular geometric including burr, rollover, incline, bulge become deteriorated with increase initial size. enhances micro-scaled metals.