摘要：采用化学共沉淀法制备磁粉,以稀土铕离子掺杂的铝酸锶为发光材料,采用微胶囊法对磁粉进行荧光复合改性,探索其在无损检测领域的应用灵敏度;运用SEM、TEM、XRD、VSM和PL谱等手段对磁粉进行表征和性能检测。结果表明:化学共沉淀法制备的磁粉物相为Fe3O4,其单个颗粒尺寸约为10 nm,为纳米级近球形颗粒;其团聚体的尺寸范围为70～600 nm,为微米级聚集态;荧光改性后的SrAl2O4(Eu)-Fe3O4磁粉在近可见光激发下发射出明亮的绿色荧光(约为514 nm);荧光磁粉应用于实际微裂纹检测的灵敏度明显优于普通磁粉。
关键词：Fe3O4磁粉；荧光磁粉；无损检测；光致发光
Abstract: The magnetic powders were prepared by chemical coprecipitation method and modified by microencapsulation method，Eu2+ ion activated strontium aluminate as photoluminescence materials，to explore the sensitivity in the field of non-destructive testing ( NDT) ．The powders were characterized and tested by SEM，TEM，XＲD，VSM ( hysteresis loop) and PL spectra．The results show that the phase of magnetic powders prepared by chemical coprecipitation method is Fe3O4，and the single particle size of it is about 10 nm，and the powders are spherical particle．The size range of the aggregates is between 70～600 nm and it belongs to the micron-level aggregation state．The fluorescence-modified magnetic powders can emit bright green fluorescence ( approximately 514 nm) under near visible light excitation．The sensitivity of the modified fluorescent magnetic powders in practical microcracks detection is obviously better than that of ordinary magnetic powders．
Keywords: magnetic powder Fe3O4 ; fluorescent magnetic powders; non-destructive testing; photoluminescence
