超细石墨粉体高温高压合成金刚石研究

Study on synthesizing diamond using ultrafine graphite powder under high pressure and high temperature

为研究超细石墨粉体合成金刚石的可能性,以5000目的超细石墨粉和Fe70Ni30触媒为原料,用静态高压技术合成出金刚石。研究结果表明:以超细石墨粉为碳源材料合成金刚石是完全可行的,但在合成晶体里发现有大量缺陷存在;合成金刚石单产接近120ct,明显要高于相同合成腔体和工艺条件下合成普通金刚石的单产;晶体粒度平均为270μm左右,小于相同条件下以200目人造石墨粉为原料合成晶体的粒度。以超细石墨粉体为碳源材料合成金刚石的生产工艺等各方面影响因素有待深入研究。

In order to study the possibility of synthesizing diamond by ultrafine graphite powder, diamond crystals were synthesized under high pressure and high temperature using ultrafine graphite （mesh 5000） and Fe70Ni30 catalyst as raw materials. The results indicated that it is possible to synthesize diamond by ultrafine graphite. However, many defects were found in synthetic crystals. Moreover, the weight of synthetic diamond by ultrafine graphite could nearly reach 120 carats, which were obviously over the unit yield by graphite using in factories now. The average grit size of synthetic diamond by uhrafine graphite is 270μm, which was obviously smaller than usual diamond （mesh 200） synthesized by the same yielding conditions. We should pay more attention about the influencing factors in the process of synthesizing diamond by uhrafine graphite.