This study investigates the coupled thermal–mechanical behaviour in micro flexible cold rolling, an advanced forming process aimed at producing micro-thin metal strips with variable thickness distributions to enhance load-bearing performance in miniaturised systems.
A detailed three-dimensional finite element model was developed for 304 stainless steel strips with initial thicknesses between 100 and 500 µm, employing three modelling frameworks, specifically an athermal-mechanical model, a thermal-mechanical model incorporating deformational and frictional heat generation and a modified thermal–mechanical model that includes convective heat transfer and temperature-dependent specific heat capacity. The simulations capture the evolution of temperature and thermal stress and their influence on thickness directional springback, with parametric optimisation performed using the Taguchi method supported by intuitive and variance analyses.
The results reveal that thinner thickness regions exhibit higher peak temperatures, which increase with decreasing strip thickness and rising friction coefficient, while rolling speed has minimal impact, and the inclusion of convective effects and temperature-dependent specific heat capacity leads to 15.4 and 10.6% reductions in peak temperature and peak thermal–mechanical stress, respectively. Although the synergistic thermal effect causes only minor fluctuations in the springback ratio within ±5.7%, it significantly alters the relative importance of influencing parameters, particularly initial strip thickness and interface friction coefficient, while the optimal conditions for minimising springback remain consistent across varying thickness regions.
This work presents the first fully integrated thermal–mechanical analysis of micro flexible cold rolling and offers a theoretical foundation for process optimisation and quality enhancement in precision micro-manufacturing applications.
