4. Results and Discussion Figure 9 illustrates the progression of deformation in tubular samples for the production of a triangular part using dual-pressure loading path #1. This loading path involved three levels of internal pressurization. At level one, the tubular sample was partially formed at a pressure of 70 MPa (Figure 9a). The wider side of the resulting triangle extended 42 mm from the original tube diameter of 34.9 mm. Figure 9b shows collapsed tube samples after external pressurization.
