Properties of niobium titanium superconducting alloy
After the composition of niobium-titanium superconducting material is determined, its Tc and Hc2 values generally do not change much, and its Jc is significantly related to the microstructure produced by cold processing-aging treatment.
If the morphology, size, spacing and quantity of cold-processed dislocation cell wall and heat-treated precipitated phase can match with the quantum flux, the maximum magnetic flux pinning force will be generated (see magnetic flux pinning theory), so that the Jc of niobium titanium superconducting material can reach the maximum.
In the production of niobium-titanium superconducting material, the Jc of the superconducting material can be significantly improved after the first aging treatment after strong cold deformation. When the cold deformation aging treatment for many times, after the last limitation of pure titanium niobium pure titanium products manufacturing process flow chart of niobium superconducting materials further processing technology of cold deformation of n (see niobium iron many aging heat treatment technology of superconducting materials), can produce ideal microstructure (see titanium niobium superconducting material microstructure), the Jc gain greater value. In the early 1980s, the Jc of NbTi50 / Cu multi-core composite superconducting line developed by Northwest Research Institute of Nonferrous Metals in China was as high as 3.5 ×105A/cm2(5T, 4.2K, 10-14 ω •m criterion).
From the end of 1980s to the beginning of 1990s, the Jc of NbTi46.5 / Cu multi-core composite niobium-titanium superconducting material increased to a new level of (3.7-3.8)×105A/cm2(4.2K, 5T, 10-14 ω •m criterion). Jc value of commercial niobium-titanium superconducting material is not higher than 2.75 ×105A/cm2(4.2K, 5T, 10-14 ω •m criterion).