Study on Nb APC Nb-Ti Superconductor Made by Powder Metallurgy

The incorporation of Artificial Pinning Centers (APC) into Nb-Ti superconductors has been demonstrated as an effective method for enhancing their performance. Typically, APC Nb-Ti superconductors are fabricated using the PowderMetallurgy technique, which involves the utilization of fine Nb-Ti powder and APC powder as precursors. The efficacy of APCs is largely determined by their size, quantity, and distribution, which are crucial factors influencing the Critical Current Density (Jc) of APC Nb-Ti superconductors. In this study, various batches of Nb-Ti and Nb powder with particle sizes ranging from 15 to 150 microns and different ratios were employed to produce APC Nb-Ti superconductors. We explored the influence of Nb particle size and shape on the superconducting properties and microstructure of APC Nb-Ti superconductors. Experimental findings indicate that Nb-APC Nb-Ti superconductors exhibit enhanced Critical Current Density at lower magnetic fields. Furthermore, reducing the processing strain notably improves the Critical Current Density. The Critical Current Density of NbAPC Nb-Ti superconductors reached 7730 A/mm2 at 2T, following a heat treatment of 400 ℃ for 20 hours, repeated three times, and utilizing Nb powder with sizes between 50 and 150 μm