Surface oxidation characteristics of nickel-base superalloy GH4169 powder

The effect of temperature on surface oxidation characteristics of nickel-base superalloy GH4169 powder was investigated by field emission scanning electron microscope (FE-SEM)，energy-dispersive spectroscopy (EDS)，X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). The results show that the surface of the GH4169 superalloy powder is partially oxidized at room temperature（RT），and on the surface there are elemental states dominated by Ni，Cr，Ti and Nb, and hydroxide/oxide dominated by Ni(OH)2，Cr2O3，TiO2 and Nb2O5。With the temperature increasing (150～250 °C) ，the peaks of Ni，Cr，Ti and Nb elements become weaker，the degree of oxidation is slightly increased and the surface of powder is partially oxidized. When the temperature reaches to 350 °C， the peaks of Ni，Cr，Ti，and Nb elements are all disappeared，and the surface of powder is fully oxidized. The oxide layer thickness is about 5 nm, and is mainly composed of Ni(OH)2，Cr2O3，TiO2and Nb2O5. The effect of temperature on oxidation characteristics of the GH4169 superalloy powder is significant，and the maximum treatment temperature of the GH4169 superalloy powder used for this study is no more than 250 °C exposed within 1 h under atmospheric conditions.