利用扫描电镜(SEM)和透射电镜(TEM)对Ti6Al4V(TC4)合金表面激光重熔的NiCrBSi/TiN涂层稀释区与熔覆区界面组织进行了分析。结果表明,稀释区与熔覆区界面区域的快速凝固组织为Ti-Ni,Ti-Cr金属间化合物和Ti-N化合物。Ti-Ni,Ti-Cr金属间化合物中部分的Ti,Ni原子被熔池中的Cr,Al等原子所取代,形成了以Ti2Ni,TiNi和Cr2Ti为基的化合物。Ti-N两相之间的Ti2.6Ni1.33组织有许多的“蜂窝”,最大尺寸约为40 nm,较小的为10 nm以下。这是由于熔体中的“气团”来不及逸出,在快速凝固中滞留的结果。

The microscopic morphology and microstructure of the phase between the dilution zone and the clad zone in laser remelting NiCrBSi/TiN layer on Ti-6Al-4V alloy surface were characterized by use of scanning electron microscope (SEM) and transmission electron microscope (TEM). The experimental results show that the microstructures between the dilution zone and the clad zone are Ti-Ni, Ti-Cr intermetallic and Ti-N compounds. The Ti and Ni atoms of Ti-Ni and Ti-Cr intermetallic compounds are replaced partly by Cr, Al etc., forming Ti2Ni, TiNi and Cr2Ti type intermetallic compound during laser remelting. Honeycomb structure exists in the Ti2.6Ni1.33 between Ti-N with maximum size around 40 nm and minimum size around 10 nm.The origin is that “gas mass” can not escape and keeps in the microstructure under rapid solidification.