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

A Zn modified amorphous–nanocrystalline coating was fabricated on a Ti–6Al–4V alloy by laser cladding of the Co–Ti–B4C–Zn–Y2O3 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 Co5Zn21 and TiB2 nanocrystalline phases were produced through in situ metallurgical reactions, which blocked the motion of dislocation, and TiB2 grew along (010), (111) and (024). The Co5Zn21 nanocrystals were produced attached to the ceramics, which mainly consisted of the Co nanoparticles embedded in a heterogeneous zinc, and had varied crystalline orientations.