金刚石/Fe_3O_4磁性聚集磨料的制备与表征

以表面缺陷较多的金刚石微粉为实验原料,用混合强酸对其表面进行处理使其羟基和羧基化。然后采用化学沉淀法制备出金刚石/Fe_3O_4磁性聚集磨料。用XRD、SEM、EDS、IR、Raman、VSM等检测方法对样品的结构、形貌、元素组成和磁性能进行了表征。结果表明,Fe³⁺与金刚石表面的含氧基团的络合作用,使金刚石微粉表面被Fe_3O_4颗粒包裹,形成不规则类球形金刚石/Fe_3O_4磁性聚集体。当金刚石加入量占理论生成总固体量的9. 4wt%时,磁性聚集磨料展现较高的磁性能。其饱和磁化强度(M_s=60. 8 emu/g)与同等工艺制备的纯Fe_3O_4样品(M_s=66. 3 emu/g)接近。

Preparation and Characterization of Diamond/Fe3O4 Magnetic Aggregate Abrasives

Micro-diamond powders with abundant surface defects was treated using mixed acid as an oxidative agent to produce hydroxyl and carboxyl groups on their surface. A magnetic aggregate abrasive consisted of micro-diamonds and ferriferous oxide was prepared through the chemical precipitated reaction, which involved in micro-diamonds and ferric chloride as the precursors added in the reactive solution. The structure, morphology, elemental composition and magnetic properties of the abrasive were characterized using a number of techniques, including powder XRD, SEM, EDS, IR spectroscopy, Raman technique and VSM. The results indicate that the micro-diamonds' surface was closely coated by particle film of ferriferous oxide, and these abrasive particles constituted an irregular spherical aggregation because of the action between the individual particles. The complexation reaction between the ferric ion and the oxygen-containing functional groups of micro-diamonds play a key role in formation of diamond/ferriferrous oxide composite. The magnetic aggregated abrasive particles exhibited excellent magnetic properties. Especially, the saturation magnetization of the abrasive ( M s=60.8 emu/g) was as high as that of pure ferriferrous oxide ( M s=66.3 emu/g) obtained the similar preparation, when the weight of micro-diamonds was 9.4wt% of the total weight.