用两种不同的方法制备了球形及条形颗粒的Fe3O4磁悬液, 并用X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)分析测试手段对制备的样品进行了表征。将制备的两种形状的Fe3O4磁悬液用于对制作的裂纹试块进行磁粉检测。试验结果表明: 在磁化过程中, 纯球形纳米Fe3O4向缺陷漏磁场处聚集较快, 裂纹显示清晰具体; 撤走外加磁场后, 受磁悬液的扰动, 缺陷磁痕被破坏; 使用纯球形纳米Fe3O4磁悬液所得缺陷磁痕显示不如使用条形纳米Fe3O4磁悬液所得磁痕显示清晰。

Fe3O4 magnetic fluids of two different shapes of sphere and square were prepared by two different methods. The samples were characterized with XRD, TEM, and SEM. Fe3O4 magnetic fluids of two different morphologies were used for the magnetic particle detection of the artificial test block. The results show that during the magnetization process, sphere Fe3O4 of water based magnetic fluids was gathering to the defect leakage magnetic field faster than that of square one and crack indication was exactly clear. After withdrawing the external magnetic field, the defect indications were destroyed by the disturbance of the fluids. The defect indications by using pure spherical nano Fe3O4 magnetic fluids were not as clear as that with using square nano Fe3O4 magnetic fluids.