Seven MgB₂ bulk superconductors with good superconductivity and crystallinity were prepared under the pressure of 50 MPa at 950 C and different sintering durations (15 ∼ 240 min) by spark plasma sintering (SPS), with the onset critical temperature (T _c,onset) around 37.5 K. The superconducting properties and microstructure measured from the facets perpendicular (PeF) and parallel (PaF) to the compression direction of the SPSed MgB₂ bulk samples were also analyzed to investigate the effect of the sintering duration on the MgB₂ bulks and the discrepancy between the PeF and the PaF. The optimum performance was obtained from the sample prepared for 45 min for both facets, and the critical current density (J _c) measured from the PeF and the PaF are 364 kA cm⁻² and 344 kA cm⁻² in self field at 20 K, respectively. The PeF exhibits better J_c performance than the PaF at low fields and the PaF exhibits better J _c performance than the PeF at high fields. It can be concluded that the sintering duration affects the properties of the PeF mainly by changing their crystallite size. While for the PaF, the sintering duration mainly affects the microstructural defects, such as cracks, pores and secondary phase particles, thus further affecting their J _c performances. In terms of the flux pinning mechanism of the SPSed MgB₂ bulk samples, the PaF is less susceptible to sintering duration than the PeF, and the better J _c performance of the PaF at high fields is due to the stronger grain boundary pinning. It can be also found that the point pinning being stronger at higher temperature is the result of the decreasing anisotropy of MgB₂ bulk samples with the temperature.

在950℃，50 MPa的压力下，通过火花等离子体烧结（SPS）在不同的烧结持续时间（15〜240 min）下，制备了七个具有良好超导性和结晶性的MgB ₂块状超导体，其起始临界温度（T _c，起始）大约37.5 K左右。还分析了从垂直于（S）MgB ₂块体压缩方向的小平面垂直（PeF）和平行于（PaF）的小面测量的超导性能和微观结构，以研究烧结时间对MgB ₂块体的影响。 PeF和PaF之间的差异。从45分钟准备的两个面的样品以及临界电流密度（J 从PeF和PaF测得的_c）在20 K的自电场中分别为364 kA cm ^-2和344 kA cm ^-2。的PEF表现出更好Ĵ _Ç 在低场性能比PAF和PAF表现出更好Ĵ _Ç在高场性能比PEF。可以得出结论，烧结时间主要通过改变它们的微晶尺寸来影响PeF的性能。对于PaF，烧结时间主要影响显微组织缺陷，例如裂纹，气孔和次级相颗粒，从而进一步影响其J _c性能。关于SPSed MgB ₂的磁通钉扎机制大量样品中，PaF的烧结持续时间比PeF少，并且在高磁场下PaF的J _c性能更好，这是由于较强的晶界钉扎。还可以发现，较高温度下的点钉扎更强是MgB ₂块状样品随温度降低的各向异性的结果。