激光熔覆Ni基涂层的稀释区与熔覆区界面形态及组织

Form and constituent of interfaces in laser remelted Ni

在Ti6Al4V合金表面进行了激光重熔NiCrBSi/TiN,NiCrBSi/TiC喷涂层实验,利用扫描电镜和X射线衍射仪等手段对稀释区与熔覆区界面进行了观察。结果表明:NiCrBSi/TiC重熔层的稀释区与熔覆区界面平直,而NiCrBSi/TiN重熔层的稀释区与熔覆区的界面不复存在,是共晶组织和颗粒组织的混合区。分析认为,[C]、[N]活性原子在高温流动熔体内的不同行为,强烈地影响稀释区与熔覆区的界面性质。NiCrBSi/TiC、NiCrBSi/TiN激光重熔层中稀释区与熔覆区界面TiC和TiN相的形成,遵循化学反应的基本规律,即电负性原则。

Laser remelted NiCrBSi/TiN and NiCrBSi/TiC coatings were fabricated on the substrate of Ti-6Al-4V alloy. The interface between the dilution and clad zones is observed using scanning electron microscope(SEM) and X-ray diffraction(XRD). The results show that the interface characterization of NiCrBSi/TiC is straight, and the interface characterization of NiCrBSi/TiN coating occurs, and a mixed zone consisting of eutectic and grain microstructure comes into existence. The action of active atoms? in high temperature melt-fluid causes change in the interface characterization, and greatly affects the quality of the interfaces. The way TiC and TiN is formed agrees to the basic principle of chemical reactions, namely electronegative rule.