Abstract:
Influence of temperature on the oxidation behaviors of the nickel-based superalloy powders was investigated by chemical analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results indicate that the oxygen content by mass fraction of the nickel-based superalloy powders is 0.012% at room temperature (RT). The oxidation layer partly covers the powder surface in the formation of metallic element (Ni, Cr, Ti) and oxidation state (Ni(OH)
2, Cr
2O
3, TiO
2). With the increase of temperature from RT to 150 ℃, the oxygen content seems stable. As the temperature rises to 250 ℃, the oxygen content by mass fraction is 0.034%, showing the obviously increase. The powder surface is completely covered by the oxidation layer at 250 ℃, which is mainly composed of Ni(OH)
2, Cr
2O
3, and TiO
2. The elevated temperature significantly affects the oxidation behaviors of the nickel-based superalloy powders, the reasonable control of temperature can obtain the powders with low oxygen content. In this study, the maximum post-process temperature of the nickel-based superalloy powders exposed to the air is 150 ℃.