Effect of RE oxides on the microstructure of the coatings fabricated on titanium alloys by laser alloying technique

Composite coatings were fabricated on the surface of pure titanium and Ti–6Al–4V by laser alloying with boron and graphite powders. The results show that with the addition of Ce 2 O 3 and Y 2 O 3 , not only the compounds but also the microstructures of the coatings are refined compared with that without rare earth (RE) oxides. The mechanism of the microstructural refinement by the addition of RE oxides is discussed in this paper.