Differential flow velocities control method for push-bending of the thin-walled tube with a 0.9D bending radius by differential lubrication

The smaller the relative bending radius of bent tube, more difficult tube blank is to be bent. In this paper, push-bending process for aluminum with a 0.9D was analyzed through simulation. There tangential tensile stress concentration occurring at front endpoint intrados, which increased risk cracking. That because tube’s extrados moves less angular distance than its intrados by uniform lubrication method, causing excessive deformation cross-section. Therefore, differential method using lubricant larger friction coefficient and proposed increase velocity extrados. It found that helped avoid thinning simulations. Furthermore, experiments 5A02 alloy were carried out investigate effect. experimental results showed effectively avoided cracking, agreed simulation results.