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用Nb47Ti片和Ta片制备NbTiTa/Cu超导线材,在三次热挤压和热处理后NbTiTa超导线材的芯丝中Ta成豆状和条带状,Ta和Nb47Ti间的互扩散很小。在NbTiTa超导芯丝中α-Ti钉扎中心成条带状,厚度为5～10nm,间距为20～50nm,讨论了α-Ti钉扎中心的尺寸和间距对磁通钉扎效果的影响。结果表明,当温度降到3.0K时NbTiTa/Cu超导线材在高场中的临界电流密度反映出Ta在芯丝中作为非超导相依然能够起到提高线材的上临界场和高场中临界电流密度的作用。不同直径的NbTiTa/Cu超导线材的临界电流密度表明,较大的最终附加应变对临界电流密度的提高具有重要意义,如果进一步减小线材的直径,线材的临界电流密度可以继续提高。
The NbTiTa / Cu superconducting wire was made by Nb47Ti and Ta films. The Ta in the core of NbTiTa superconducting wire became soya-shaped and banded after three times of hot extrusion and heat treatment. The mutual diffusion between Ta and Nb47Ti was very small. In the NbTiTa superconducting core wire α-Ti pinning center into a strip, the thickness of 5 ~ 10nm, the spacing of 20 ~ 50nm, discussed the α-Ti pinning center size and pitch on the flux pinning effect . The results show that the critical current density of NbTiTa / Cu superconducting wire in high field decreases when the temperature drops to 3.0K, indicating that Ta as a non-superconducting phase in the core wire can still improve the upper critical field and high field The role of critical current density. The critical current densities of NbTiTa / Cu superconducting wires with different diameters show that the larger final added strain is of great importance to the increase of critical current density. If the diameter of the wire is further reduced, the critical current density of the wire can be further increased.