METHOD FOR REALIZING A CUBE TEXTURED, LOW ASPECT RATIO METAL PROFILE WITH RECTANGULAR CROSS SECTION, AS SUBSTRATE FOR A SUPERCONDUCTOR WIRE, AND RELATED PRODUCT OBTAINED BY SAID METHOD

摘要

The invention concerns a method for realizing a cube textured, low aspect ratio metal profile with rectangular cross section, as substrate for the production of a superconductor wire, having a rectangular cross section with a thickness between 0.1 mm and 1 mm, with all four surfaces available for the growth of epitaxial films by means of physical or chemical techniques, and realized by a face centred cubic (fee) metal, having a cube texture, obtained by cold rolling with thickness reduction of not less than the 90%, followed by longitudinal cutting, and by a final high temperature recrystallization heat treatment in vacuum or in reducing atmosphere, said method comprising the steps of : a. taking as starting material an ingot of a selected metal in the form of a cylinder or parallelepiped of purity not less than 99.9% and with a thickness of at least 8 mm; b. heat treating the ingot according to step a. in high vacuum or in reducing atmosphere at a temperature T0 (expressed in °C) equal to about TM/2, wherein TM is the melting temperature of the metal (expressed in °C), for a time t0 variable between 1 and 12 h, the treatment being prolonged if alloys are used, favouring homogenization; c. cold rolling the ingot, with a reduction rate Δd/d = 5-10% to the desired thickness, reaching a deformation degree exceeding 90%, taking into account that in general the final cube texture improves with increasing the deformation degree; d. cutting longitudinally at room temperature the rolled product, to avoid its recrystallization, and at a speed low enough not to deteriorate the deformation texture obtained by the previous steps to obtain a profile with the desired aspect ratio; e. recrystallizing the profile in high vacuum or in reducing atmosphere at a temperature (expressed in °C) T_M/2 T₂ T_M to obtain a cube textured profile, taking into account that in general cube texture improves with increasing annealing time and temperature up to the stability limit of the primary recrystallization.