| 摘要 |
PURPOSE:To lower a wire break-down rate in wire drawing by softening a wire material at a specific temperature and drawing it thereafter while cooling it by a liquid nitrogen. CONSTITUTION:A Nb, Ti alloy rod is fitted to a copper pipe, etc. and many fitted matters are inserted into a copper billet. The billet is radially reduced by hot extrusion to soften the extruded wire rod at a <=500 deg.C. The wire rod is successively drawn while cooling it by a liquid nitrogen. Because of the <=500 deg.C softening, the Nb, Ti filament is prevented from the intrusion of a intermetal compound of Nb, Ti-metallic Cu. Further, because of the low temperature drawing, a nucleus formation due to the intermetal compound formation is restricted, and the formation of intermetal compound of Nb, Ti alloy-metallic Cu is reduced to a small amount. Accordingly, the break down rate in wire drawing is extremely lowered.
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