Stability research on spinning of ultra-thin-wall aluminum alloy tube

Abstract

In this paper, the instability in spinning process of ultra-thin-wall tube is analyzed, and the influence law of different parameters of roller and main process parameters in spinning forming process. Firstly, the forward spinning finite element model of ultra-thin wall tube is established and its reliability is verified. It is concluded that the instability of ultra-thinwall aluminum alloy tube during spinning is caused by its poor rigidity and material flow disorder. The effects of different parameters of roller (roller diameters, roller forming angles and roller corner radii) and the main process parameters (feed rates, friction coefficients and thinning rates) on the equivalent plastic strain and diameter expansion amount in spinning forming process were investigated. The results show that the influence of each parameter on the stability of ultra-thin-wall is quite different. The influence of roller corner radius is stronger than roller diameter and much stronger than roller forming angle. The influence that feed rate does the expansion amount to exist a minimum value. The friction coefficient and thinning rate have positive correlation with expansion amount. The optimum combination of process parameters was further determined, and the accuracy of the results was verified by experiments, which provided reference and guidance for actual production.

Experimental estimation and numerical optimization of ‘cylindricity’ error in flow forming of H30 aluminium alloy tubes

“…For the starting and higher ranges, its effect on cylindricity error is opposite to the middle range. This is further corroborated by the results reported by Wang et al [23] who have studied the spinning stability as a function of the process parameters. It has been found that the increase in the feed rate causes a decrease in the equivalent plastic strain and it is predicted that a larger or smaller feed rate than the optimum one will result in excessive diameter expansion.…”