掺杂立方氮化硼对金刚石聚晶致密化和显微结构的影响

THE EFFECT OF cBN INCLUSIONS ON THE DENSIFICATION AND MICROSTRUCTURE OF FINE-GRAINED POLYCRYSTALLINE DIAMOND COMPACT

以小于 0 .5 μm的金刚石和氮化硼 (以下简称cBN)微粉为原料 ,在 6.0GPa和 145 0～1480℃保温 30min的工艺条件下 ,成功地烧结出晶粒尺寸小于 1μm、以WC/Co硬质合金为衬底的金刚石聚晶。研究了cBN掺杂对金刚石基质密实化和显微结构的影响。研究表明 ,cBN可以有效地抑制金刚石异常长大。细晶而且致密的金刚石聚晶有优异的力学性能。

Commercially available synthetic powders of diamond and cubic boron nitride less than 0 5μm were used as the raw materials.Sintering of a fine grained polycrystalline diamond compact with grains less than 1μm in size was successfully carried out by making a laminate on a WC/Co powder compact under sintering conditions of 6 0GPa and 1450℃ to 1480℃ for 30min.The effect of cBN inclusions on the densification and microstructure of the polycrystalline diamond compact was investigated in detail.Results showed that cBN played the role of suppressing abnormal grain growth during sintering.The wear resistance of sintering diamonds with different volume fraction of cBN under sintering conditions of 6 0GPa and 1360℃ to 1480℃ for 30min was measured.The microstructure of the polycrystalline diamond compact was observed by scanning electron microscope(SEM)