Effect of yttrium and oxygen combination on the microstructure of Zr-Cu-Ni-Al metallic glass

The traditional wisdom seems to suggest that yttrium can be added with oxygen to form inert oxides to prevent oxygen contamination during the MGs fabricated process. Here, the effects of yttrium-doped on the microstructure evolution of the Zr-based MG composite coatings were systematically investigated by laser melting deposition technology. We firstly reported that the yttrium oxides were not completely in an inert state, but as the heterogeneous nucleation core with epitaxial growth of the CuZr intermetallic compound with simple cubic structure, under the influence of sufficient heat input and a low cooling rates, while would be inhibited with insufficient thermal input and high cooling rates. • MGMC coatings with crystalline phases embedded in amorphous matrix were prepared by laser cladding. • We provide an explanation for the inconsistency in the sizes of the yttrium oxides particles observed by SEM and TEM. • Yttrium oxides was observed for the first time to be heterogeneous nucleation core. • This work provides important supplement for the effect of yttrium-doped on the GFA of Zr-based MG.