It has been performed the physical simulation of the isothermal forming process of Ti alloy frame structure with high rib and thin web and with Z, Ч and H cross-section and with different height/width ratios. In this survey it is found that the ability of filling die space is increased with the increase of deformation
in all cases, whether which section of the forming part is or which shape the blank is, the metal flowing speed to convex arc and broad cavity is faster than that to concave arc and narrow cavity. The blank shape should be designed in accordance with the principle to meet the needs for metal filling and the shortest transferring paths. The use of Al alloy to simulate Ti alloy isothermal forming process can truthfully reveal Ti alloy flowing and filling ability in isothermal forming process.