初始原料hBN的结晶度及添加剂对cBN合成的影响

Influence of Starting Materials hBN Crystallinity and Additive LiH on cBN Synthesis

在压力为4.5-5 GPa,温度为1 500-1 700℃内,以Li3N为触媒研究了结晶程度不同的hBN在有或无添加剂LiH情况下对cBN合成难易程度的影响.通过X-光谱对初始原料进行了分析并用显微镜观察了合成产物.结果表明：在不添加LiH的情况下,结晶度高的hBN较容易合成cBN,而添加LiH后,与上述结果相反,结晶度较低的hBN较容易形成cBN.

The influence of hBN crystallinity and additive LiH on cBN synthesis with Li3N as catalyst under the pressure of 4.5~5 GPa and the temperature of 1 500~1 700 ℃ was investigated.X-ray diffraction was used to characterize the properties of the starting materials and products.The synthesized samples were observed by optical microscopy（OM）.The results indicated that the higher crystalline hBN was preferred to transform to cBN.However,when LiH was put into the system,the results were reversed and the lower crystalline hBN was preferred to cBN synthesis.