用铁基烧结助剂制备金刚石聚晶的研究

Study on the Preparation of Polycrystalline Diamond Using Fe-based Sintering Agents

通过高温高压下金刚石再生长烧结方法,采用细粒度金刚石微粉作原料,铁基金属微粉作烧结助剂,在六面顶超高压设备上进行了金刚石聚晶的制备。研究了铁基金属和金刚石微粉体系再生长烧结的温度压力条件,并通过高倍光学显微镜、扫描电镜(SEM)、X-ray衍射、Raman光谱等测试手段对金刚石聚晶样品进行了内部成分和微观形貌分析。研究结果表明,在5.8GPa,1550℃条件下制备的PCD材料内部比较均匀致密。X-ray衍射和Raman光谱测试结果表明,在更高的温度条件下制备的样品内部有少量的石墨化。另外,样品内部还有部分碳化铁的存在。因此,我们认为,用Fe基烧结助剂制备的PCD材料内部除存在金刚石的自成键外,还有金刚石与金刚石之间通过铁碳键把金刚石烧结在一起的一种机制。

By the re-growth and high-pressure sintering method, using fine diamond powder as raw material and Fe - based metal powder as sintering agent, polycrystalline diamond (PCD) was prepared in a cubic press. The sintering conditions for the system of diamond and Fe-based fine powder were studied. The composition and micro - structure of the PCD samples were characterized by optical microscope, SEM, X-ray diffraction and Raman spectra. The results showed that PCD sample prepared at 5. 5 GPa and 1550℃ was even and compact. From X-ray diffraction and Raman spectra, a small quantity of graphite was observed in the sample prepared at higher temperature. A few Fe3C was also found in the obtained PCD samples. So, the mechanism of forming PCD using Fe-based agents can be explained by the existence of the strong D-D bonds, as well as a few Fe-C bonds existing in the PCD samples.