磁头抛光液用金刚石超微粉研究

利用原子吸收光谱（AAS）、电感耦合等离子体质谱（ICP-MS）、粉晶X射线衍射（XRD）、激光拉曼光谱（RAMAN）、透射电子显微镜（TEM）等手段对磁头抛光液用金刚石超微粉进行了研究。AAS和ICP-MS测试结果显示，静压触媒法合成的金刚石超微粉中主要含有硅的氧化物和铁、镍、铝等一些金属杂质；XRD图谱中除了金刚石尖锐的特征峰以外，在2θ=35.6°, 39.4°, 59.7°处还观察到SiO₂的特征衍射峰，表明金刚石超微粉结晶程度高、硬度大，但其中含有一定量的硅氧化物物相；在RAMAN图谱中除了金刚石的特征谱外在1 592 cm-1处可观察到宽化了的石墨的特征谱；从TEM照片可以观察到微粉粒度分布在0.1～0.5 μm之间，但是颗粒锋利棱角的存在有利于提高抛光效率。金刚石超微粉的高硬度、强的耐磨性、高的抛光效率使其适于作为磁头抛光液磨料使用。但是，杂质的存在影响抛光效率、缩短抛光液寿命；宽的粒度分布降低了抛光的精度。因此，使用前必须对金刚石超微粉进行提纯、分级处理；使得金刚石超微粉的纯度达到99.9％以上、有害杂质SiO₂的含量不超过0.01%，并且使超微粉的平均粒径为100 nm且大于200 nm的颗粒在总的颗粒中小于2%。

The Study of Ultra-Fine Diamond Powder Used in Magnetic Head Polishing Slurry

In the present paper, atomic absorption spectrometry(AAS), inductively-coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and laser Raman spectroscopy (RM) were employed to study the commercial ultra-fine diamond powders prepared by the static pressure-catalyst method and used in magnetic head polishing slurry. The results of AAS and ICP-MS indicated that there were silicon oxide, Fe, Ni, Al and some other metal elements in the ultra-fine powders. XRD patterns showed the peaks of SiO2 at 2theta = 35.6 degrees, 39.4 degrees and 59.7 degrees and diamond sharp peaks in agreement with the results above. Diamond sharp peaks implied perfect crystal and high-hardness beneficial to high-efficiency in polishing. The broader Raman band of graphite at 1 592 cm(-1) observed by Raman analysis proved graphite existing in the diamond powders. In the TEM images, the size of ultra-fine powders was estimated between 0.1 and 0.5 microm distributed in a wide scope, however, sharp edges of the powder particles was useful to polish. The ultra-fine diamond powders have many advantages, for example, high-hardness, well abrasion performance, high-polishing efficiency and being useful in magnetic head polishing slurry. But, the impurities influence the polishing efficiency, shortening its service life and the wide distribution reduces the polishing precision. Consequently, before use the powders must be purified and classified. The purity demands is 99.9% and trace silicon oxide under 0.01% should be reached. The classification demands that the particle distribution should be in a narrower scope, with the mean size of 100 nm and the percentage of particles lager than 200 nm not over 2%.