In this research, the effect of adding 2.5, 5.0 and 10 wt% niobium (Nb) as a binding agent was investigated for High Pressure-High Temperature (HPHT) sintering of polycrystalline diamond (PCD). Samples were sintered at 1750 °C and 7.7 GPa. Detailed characterization of the as-sintered materials revealed a uniform dispersion of the Nb additives in the diamond matrix and no interfacial cracking was observed. Higher concentration of binder increased tendency to intergranular failure. The formation of NbC and NbC_0.84 phases after sintering was identified, indicating that some of the matrix carbon may have undergone graphitization.

中文翻译：

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铌是通过高温高压（HPHT）烧结的多晶金刚石（PCD）的新型粘合剂

在这项研究中，研究了添加2.5、5.0和10 wt％的铌（Nb）作为粘结剂对多晶金刚石（PCD）的高压高温（HPHT）烧结的效果。样品在1750°C和7.7 GPa下烧结。烧结后材料的详细表征表明，Nb添加剂在金刚石基体中均匀分散，未观察到界面裂纹。较高的粘合剂浓度增加了晶间破坏的趋势。烧结后鉴定出NbC和NbC _0.84相的形成，表明某些基体碳可能已石墨化。