Infiltration-Growth Processing of NdBa2Cu3O7-delta Superconductor
Infiltration-Growth Processing of NdBa2Cu3O7-delta Superconductor
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DOI：
10.1111/j.1151-2916.1999.tb02191.x
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发表时间：
2004-12
影响因子：
3.9
通讯作者：
N. H. Babu;T. Rajasekharan;L. Menon;S. Malik
中科院分区：
文献类型：
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作者：
N. H. Babu;T. Rajasekharan;L. Menon;S. Malik
NdBa 2 Cu 3 O 7-δ (Nd-123)超导体通过液相渗透到成形预制体中，然后通过Nd-123的包晶形成温度缓慢冷却的过程，获得了具有微米级球形Nd 4 Ba 2 Cu 2 O 10 （Nd-422）包体的高度织构微观结构。该过程在高纯氩气中进行（氧气最多为4ppm），以减少低碳固溶体的形成。该工艺的一个主要优点是它最大限度地减少了液体中Nd-422粗化的可能性。结果表明，在高度织构化的Nd-123基体中，Nd-422夹杂物呈球状分布，80%的夹杂物直径小于1 μm。由于目前的工艺消除了样品内部的收缩和大空洞，因此可以制造具有良好尺寸公差和高jc的三维复杂形状物体。本文测量了Nd-123/Nd-422复合材料的临界电流密度，并结合材料的微观结构对其进行了讨论。
NdBa 2 Cu 3 O 7-δ (Nd-123) superconductor has been processed to obtain a highly textured microstructure with micrometer-sized spherical Nd 4 Ba 2 Cu 2 O 10 (Nd-422) inclusions through a process that involves the infiltration of liquid phases into a shaped preform followed by its slow cooling through the peritectic formation temperature of Nd-123. The process was carried out in high-purity argon (maximum of 4 ppm of oxygen) to reduce the formation of low-T c solid solutions. A major advantage of the process is that it minimizes the possibility of Nd-422 coarsening in the liquid. The result is a very uniform distribution of nearly spherical Nd-422 inclusions with 80% of the particles having a diameter less than 1 μm, in the highly textured Nd-123 matrix. Since the present process eliminates shrinkage and large hollows within the interior of the samples, it can enable the fabrication of 3-dimensional complex-shaped objects with good dimensional tolerance and high J c for applications. The critical current densities in the Nd-123/Nd-422 composites have been measured and the values obtained are discussed in the context of the microstructure of the material.