【摘要】 利用Ｘ射线衍射法分析了７种六方氮比硼原料的结晶度、晶粒度和晶格常数，研究了高温高压下六方氮比硼（ｈＢＮ）向立方氮比硼（ｃＢＮ）的转化行为和转化率。结果表明，结晶度高和晶粒度细的六方氮化硼易于转化，有利于ｃＢＮ的成核。更多还原

【Abstract】 Cubic boron nitride(cBN)is synthesized from seven kinds of the hexagonal boronnitride(hBN)under a pressure of 4.6GPa and a temperature of 1600℃ with catalyst by using acubic anvil press. The contrast to the standard curve is made in the present work,and the conver-sion yields of different kinds of hBN to cBN are measured by powder X-ray diffraction,The rela-tive degree of three-dimensional order of various hBN raw materials is determined.Graphitizationindex(G.I value),crystalline grain size,and unit cell cell constants are calculated on data ofXRD,and their effects on the conversion yields of hBN to cBN investigated.The hBN with bet-ter crystallinity and smaller crystalline grain size shows higher conversion rate to cBN.On the phase transformation from hBN to cBN, we suggest a direct conversion with two-dimensional nu-cleation as a possible mechanism.The theoretical description based on the homogeneous nucle-ation mechanism yields resonable results according to experimental data.更多还原