Simulation of Super-Plastic Forming Based on a Micro-Structural Constitutive Model and Considering Grain Growth
Constitutive models based on dominant mechanisms in hot forming are proposed. These models consider inter-granular deformation, grain boundary sliding, grain boundary diffusion and grain growth. New stress-strain rate relationships are proposed to predict deformation due to grain boundary sliding and grain boundary diffusion. Beside a Taylor type polycrystalline constitutive model, a visco-plastic relation in conjunction with a yield function is used to predict inter-granular deformation with much less computational costs. The proposed models are calibrated with tensile test data of AA5083 at . The calibrated models closely fit simple tension experimental data for various strain rates and strains. Then as an example the models are used to simulate a tray forming experiment. Dome heights and tray thicknesses at various positions during forming time can well predict experimental observations.
J.R. Duflou, R. Clarke, M. Merklein, F. Micari, B. Shirvani and K. Kellens
M. Farzin et al., "Simulation of Super-Plastic Forming Based on a Micro-Structural Constitutive Model and Considering Grain Growth", Key Engineering Materials, Vol. 473, pp. 610-617, 2011