硼掺入量对含硼金刚石单晶热稳定性的影响

 在铁基触媒原材料中添加不同含量的六方氮化硼，采用粉末冶金方法制备片状触媒，在六面顶压机上合成出含硼金刚石单晶。用体视显微镜对金刚石单晶的结构、形貌进行观察，并用电子探针（EPMA）和波谱仪（WDS）分析了金刚石（111）晶面的硼含量，发现金刚石表面有硼元素存在，且其含量随着触媒中掺硼量的增加而变化。在测定了含硼金刚石单晶的静压强度的基础上，采用冲击韧性测定仪和差热分析仪对不同掺硼量触媒合成出的金刚石单晶在空气中的热稳定性进行了系统的对比研究。结果表明，触媒掺硼量对金刚石的机械强度和热稳定性有重要影响，随着掺硼量的变化，其机械强度和热稳定性均存在一个最佳值。

Effect of Boron Contained in the Catalyst on Thermal Stability of Boron-Doped Diamond Single Crystals

The synthesizing diamond experiment was carried out at cubic hinge press apparatus with iron-based catalyst made by powder metallurgy, in which hexahedral nitride boron (h-BN) was doped with different proportions. Microstructures and morphologies of the diamond single crystals were observed under stereological microscope, and the boron concentration was investigated by electron probe microanalysis (EPMA) and wave distribution spectrum (WDS). It is shown that boron element exists on the (111) crystal surface of diamond, and the concentration of boron changes with boron content in the catalyst. Static compressive strength was also measured. Furthermore, impact toughness measurement, different thermal analysis (DTA), and thermal gravity (TG) analysis were performed to probe into the thermal stability of different boron-doped diamond in atmosphere. The results demonstrate that boron content in the catalyst plays a very important role in mechanical performance and thermal stability of boron-doped diamond, which possess optimum values with increase of the boron concentration.