Deformation behavior under die partitioning boundary during titanium alloy large-scale rib-web component forming by isothermal local loading

Isothermal local loading process which is an isothermal forging realized by local loading by means of partitioned die, provides an efficient approach for forming large-scale complex titanium alloy components widely used in aviation and aerospace fields. Only partial die is loaded in one local loading step, and thus the forming state near die partitioning boundary is a transition state from plastic yielding to non plastic yielding. During the local loading process, the improper die partition is easy to lead to non-acceptable shift, under-filling and folding defects which are affected by material parameters, forming conditions, mode of die partition, and so on. For the certain material and component, the mode of die partition and position of die partitioning boundary are the notably influencing factors of the forming defects. In this paper deformation behaviors under die partitioning boundary in isothermal local loading process of large-scale rib-web component of titanium alloy are studied by using numerical simulation. The reasons for the defects are analyzed on the basis of theoretical analysis and numerical simulation. The influences of mode of die partition, local loading conditions and geometric parameters near the die partitioning boundary on the forming defects are analyzed systemically. The results of the present study may provide a basis for determining die partition.