Effect of Trace O Element on High-temperature Wettability Between Ni₃Al Melt and Y₂O₃ Ceramic

Effect of trace O element on the high-temperature wettability between Ni₃Al scrap melt and Y₂O₃ ceramic at 1873 K is investigated. With the increase in O content in Ni₃Al scrap melt from 6 to 21 ppm, the equilibrium contact angle decreases from 93.3° to 88.9°. The initial surface tension and adhesive work of molten Ni₃Al scrap drop from 3153.5 to 807.4 mN m⁻¹ and from 2974.6 to 882.2 mN m⁻¹, respectively. The average spreading rate increases from 0.03° s⁻¹ to 0.17° s⁻¹. The whole wetting processes are divided into four periods. The main driving force for spreading in period (1) is the adsorption and diffusion of active atoms around the interface. Trace O content in Ni₃Al scrap has a significant impact on interfacial reactions which mostly take place in the second stage, and can accelerate the spreading process on Y₂O₃ substrate. The reaction products during wetting process are Y₃Al₅O₁₂, YAlO₃ and Al₂O₃.