High-performance and high-efficiency preparation method of tantalum alloy hyperboloid space structural member

The invention provides a preparation method of a tantalum alloy hyperboloid space structural member. The preparation method is characterized in that multi-pass radial split-flow forming and cold extrusion forming are combined; the multi-pass radial split-flow forming comprises an isothermal and isobaric step and a forming step, the isothermal and isobaric step is characterized in that a mold and a tantalum alloy blank are heated to 650 DEG C +/-15 DEG C, the vacuum degree reaches 5 * 10 Pa, and the number of extrusion passes of the multi-pass radial split-flow forming is 2-5, so that the blank is in a radial streamline structure along a curved surface. The vacuum isothermal radial split-flow forming method is provided for the first time, so that the tantalum alloy hyperboloid space structure piece obtains the required structure performance through plastic deformation; and cold extrusion and small-allowance precision cutting machining technologies are combined, so that the curved surface of the tantalum