Incremental Forming of Titanium Tubes: An Experimental Study

Incremental forming has emerged as a flexible and cost-effective alternative to conventional tube and sheet forming methods, particularly suitable for low-volume production and prototyping. In this study, an experimental investigation was carried out on the die-less incremental forming of thin-walled titanium tubes to produce a square cross-section at the tube end under room-temperature conditions.A flexible forming system was developed, consisting of a rotating internal tool mounted on a CNC milling machine, programmed to follow a predefined square path. A full factorial design of experiments (DOE) was employed to analyze the influence of key process parameters—linear feed rate, axial step, and forming depth—on wall thickness and geometric accuracy.The results showed that increasing the tool speed improved formability due to localized frictional heating and reduced springback, whereas excessive step size led to greater thinning and distortion. Statistical analysis using ANOVA confirmed the validity of the developed models, with high correlation coefficients (R² > ۰.۹۳) between predicted and experimental values. Overall, the proposed die-less incremental forming process demonstrates excellent potential for manufacturing non-axisymmetric tubular components, offering high flexibility, low tooling cost, and good dimensional accuracy.

کلیدواژه ها:

Die-less tube forming ، Incremental axial step ، Forming depth ، Wall thinning