The invention provides a preparation method of a high-strength high-
conductivity copper-
niobium multi-core composite wire. The preparation method comprises the following steps that 1,
oxygen-free
copper foil and
niobium foil are stacked in order and wound around an
oxygen-free
copper bar to obtain a copper-
niobium winding body, then, the copper-niobium winding body is installed in a first
oxygen-free copper tube, and a copper-niobium composite sleeve is obtained after seal
welding; 2, isostatic cool pressing forming is carried out, and a copper-niobium pressed formed part is obtained; 3, hot
extrusion machining is carried out to obtain a copper-niobium
extrusion bar billet; 4, multi-pass drawing
machining is carried out to obtain a copper-niobium single-core wire; 5,
sizing, shearing, straightening and acid
pickling treatment are carried out in sequence; 6, bundling assembling is carried out to prepare a copper-niobium bundle sleeve, the steps 2-5 are repeatedly executed, and the high-strength high-
conductivity copper-niobium multi-core composite wire is obtained. The initial
machining size of a niobium core wire can be lowered, the machining
hardness of materials is reduced, the machining period is shortened, and the preparation method is the novel method for preparing the high-strength high-
conductivity copper-niobium multi-core composite wire.