Preparation method for high-strength Ti6Al7Nb titanium alloy wire material

The invention discloses a preparation method for a high-strength Ti6Al7Nb titanium alloy wire material. The preparation method particularly comprises the steps that firstly, a Ti6Al7Nb titanium alloy bar billet of which the transverse structure is superior to the ETTC2A5 level is selected, placed in a box-type resistance furnace, heated at the temperature lower than the phase transformation point, subjected to heat preservation and rolled; secondly, oxide scales of the bar billets are removed, and a polygonal wire material is prepared through cold continuous rolling; thirdly, finishing rolling is conducted on the polygonal wire material, straightening and polishing are conducted, and then the high-strength Ti6Al7Nb titanium alloy wire material is obtained. According to the method, the material formability is improved by selecting an appropriate billet machining technology, and the structure property of the wire material is controlled through cooperation of a finished product machining mode and the deformation amount. Compared with a wire material obtained through a conventional hot drawing technology, the high-strength Ti6Al7Nb titanium alloy wire material prepared through the method has the advantages that the structure is uniform, the strength is high, and all properties can meet the requirements of a Ti6Al7Nb wire material for high-strength high-tenacity surgical implants such as an intramedullary needle.