Microstructure and physical properties of laser Zn modified amorphous-nanocrystalline coating on a titanium alloy

摘要

A Zn modified amorphous-nanocrystalline coating was fabricated on a Ti-6AI-4V alloy by laser cladding of the Co-Ti-B_4C-Zn-Y_2O_3 mixed powders. Such coating was researched by means of a scanning electron microscope (SEM) and a high resolution transmission electron microscope (HRTEM), etc. Experimental results indicated that the Co_5Zn_(21) and TiB_2 nanocrystalline phases were produced through in situ metallurgical reactions, which blocked the motion of dislocation, and TiB_2 grew along (010), (111) and (024). The Co_5Zn_(21) nanocrystals were produced attached to the ceramics, which mainly consisted of the Co nanoparticles embedded in a heterogeneous zinc, and had varied crystalline orientations.