Ni-Cr合金保护气氛钎焊金刚石的分析

Analysis on brazing diamond with Ni-Cr alloy in protective atmosphere

采用Ni-Cr合金在保护气氛炉中进行了钎焊单晶金刚石磨粒的试验,使用SEM对Ni-Cr合金钎焊金刚石的碳化物形貌和钎料组织进行了观察分析。结果表明:在保护气氛炉中,Ni-Cr合金可以实现金刚石的高强度连接,焊后金刚石棱角清晰、形貌完好,并在金刚石的表面生成排列较整齐的一层Cr3C2,Cr3C2的生长方向与金刚石的外露(111)和(100)晶面有一定的位向关系,在(111)晶面的碳化物形成了互成60°的关系,在(100)晶面的碳化物主要是互成90°和45°的关系。钎料组织主要是γ-Ni基体上分布有Cr7C3,其显微硬度最高达到900HV。

The monocrystal diamond was brazed with Ni-Cr alloy in furnace with protective atmosphere,and then morphology of the carbide formed on the diamond surface and structure of the solder were observed with scanning electron microscope.The results show that the high-strength bonding between diamond grit and steel matrix was realized by using Ni-Cr filler metal in furnace with protective atmosphere,morphology of the brazed diamond is in good condition and there is some orderly carbide Cr3C2 on the surface of the diamond which growth directions take on certain orientation relationship with the diamond crystal planes.It is easy to see that the growth directions of the carbide parallel with the arrangement directions of the crystal plane（111） and（100） separately.On the crystal plane（111）,the carbides take on 60°mutually,while on the crystal plane（100）,the carbides mainly present 90°or 45°each other.