摘要：
如何提高金刚石等超硬材料的耐热性对其应用具有着重要意义.本文报道了在高温高压 (HPHT, 5~6 GPa, 1620~1720 K, 3~5 min) 烧结条件下块体金刚石复合材料 (D-cBN-B4C-Co-Al-Si) 的合成和表征工作.实验结果表明,在烧结样品中存在金刚石,cBN, B4C, BxSiC, AlCo, AlN等物相.值得注意的是,合成样品的初始氧化温度为1520 K,其值远远高于金刚石,cBN和B4C的初始氧化温度.高热稳定性归因于在烧结过程中形成B—C、C—Si共价键和BxSiC固溶体.该项研究获得的成果有助于制备具有耐高温的复合超硬材料.%In industry application, increasing the heat resistance of the diamond - based material is of great significance. Here,B4C,Co,Al and Si were used as sintering additives for thefabrication of bulk diamond composites (PCD) at high temperature and high pressure (HPHT,5~6 GPa,1 620 ~1 720 K for 3 ~5 min). The X-ray diffraction characterization results show that the diamond, cBN, B4C, BxSiC, AlN and CoAl alloy can be found in the sintered sample. It is noteworthy that the onset oxidation temperature of sintered sample is about 1 520 K,which is much higher than that of diamond,cBN and B4C. The covalent bonds of B—C, Si—C and the solid-solution of BxSiC are the key to enhance high heat resistance of thesample. The obtained results in this work may be useful to prepare superhardcomposite materials with high heat resistance.
