【摘要】 本文通过扫描电子显微镜等实验手段,研究了Bi系超导材料在不同制备条件下的显微结构,着重分析了压力下(冷压、热压)样品显微结构的变化。经过压力处理,超导晶粒的平均尺寸显著降低,气孔率大幅度减少,样品密度得以极大提高,达理论密度的90--95％。在经冷压、热压处理的样品中可见到明显的晶粒择优取向排列,其形成机制是压力下的塑性流变以及晶粒的各向异性生长趋势。更多还原

【Abstract】 Microstructures of BiPbSrCaCuO superconductors prepared under various conditions were investigated by means of the scanning electronic microscope (SEM>. Focus was placed on the microstructure change of the samples treated by cold pressing and hot pressing. Due to the effects of pressure, average grain sizes in the pressed samples decreased remarkable! y, and the bulk densities increased greatly to reach 90-95% of the theoretic density. The high pressure treated samples, on the other hand, ’are found to be obvious oriented, which may result from the plastic flow under high pressure and the anisotropic growing of the superconducting grains.更多还原