为了研究金刚石中硼元素含量对合成金刚石的颜色与热稳定性的影响。以石墨粉体和Fe70Ni30合金触媒为原料,NH4HB4O7·3H2O为硼源添加剂,采用静态高温高压技术合成出金刚石。利用体视显微镜观察合成金刚石的颜色;AES检测金刚石中B元素的含量;TG—DSC进行热稳定性分析。结果表明:合成金刚石的初始氧化温度均超过837℃,最高达到917.8℃;1200℃时热失重率在59%-96%之间,放热峰值在893—1144℃之间;随着硼元素含量的增加,合成金刚石的颜色由淡黄色逐渐向黑色转变,热稳定性提高。
In order to investigate the influence of boron content on the color and thermal stability of diamond, synthesis experiments were conducted under high pressure and high temperature, using graphite, Fe70Ni30-alloyed catalyst powders as starting materials, and NH4HB4O7 · 3H2O as addictives The colors of synthetic diamond crystals were observed with the help of a stereomicroscope. The boron contents in the diamond crystals were quantitatively measured by the atomic-emitting spectrum (AES) method. Furthermore, thermal stability of synthetic diamond was analyzed by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) method. The results indicate that the synthesized diamond had the initial oxygenation temperatures of over 837℃, even up to 917.8 ℃, and the weight loss from 59% to 96% at 1200℃, but the exothermic summit of approximate 893℃, even up to 1144℃. With the increase of the boron content, the color of the diamond turned from yellow to dark, but the thermal stability of diamond got better.