Friction changing to control thickness distribution of TC4 deep cylinder by direct-reverse superplastic forming

Based on the direct-reverse superplastic forming TC4 deep cylinder, the influence to final thickness distribution of surface friction of preforming die and forming die was analysed with MSC. MARC. The results show that higher friction coefficient of preforming die can efficiently reduce the thickness of the regions which need to be thinned, resulting in a more uniform final thickness distribution along the component. Lower friction coefficient of forming die can make the sheet tend to integral formation, also resulting in uniform thickness distribution. According to the results of the simulation, the friction of preforming die was increased by machining and the friction of forming die was decreased by spraying lubricant. The aerospace TC4 deep cylinder with uniform thickness (1.50-1.78 mm) was fabricated by direct-reverse superplastic forming experiment, compared to the thickness distribution (1.18-2.24 mm) of common direct-reverse superplastic forming, the friction modifying direct-reverse superplastic forming was more efficient to form the uniform thickness components.