分别对以Si、Ni为粘结剂及纯镍为粘结剂的人造金刚石聚晶作了显微结构的观察。结果表明:前者是以生成的SiC和镍硅相起粘结作用,因此,这种聚晶有较好的热稳定性及较大的脆性;后者是以镍的固溶体(Ni)起粘结作用,所以韧性较好.但是,镍与金刚石的热膨胀系数相差甚大,这似乎是使得镍聚晶不宜在温度较高的环境中使用的原因。最后,本文对提高聚晶的质量提出了参考意见. The microstructures of synthetic diamond polycrystalline with Si and Ni as binder and pure nickel as binder were observed. The results show that the former is based on the bonding between SiC and NiSi. Therefore, the polycrystal has good thermal stability and high brittleness. The latter is based on Ni solid solution However, the large difference between the coefficients of thermal expansion of nickel and diamond appears to be the reason why nickel polycrystalline should not be used in the higher temperature environment. Finally, this paper puts forward some suggestions for improving the quality of polycrystalline.