Oxidation behavior of high Hf nickel-based superalloy in air at 900, 1000 and 1100℃

作者：Jiu-han Xiao; Ying Xiong; Li Wang; Xiang-wei Jiang; Dong Wang^*; Kai-wen Li; Jia-sheng Dong; Lang-hong Lou

来源：International Journal of Minerals,Metallurgy and Materials, 2021, 28(12): 1957-1965.

• superalloy
• hafnium
• high-temperature oxidation
• diffusion

To investigate the oxidation behavior of a nickel-based superalloy with high hafnium content(1.34 wt%), this study performed isothermal oxidation tests at 900, 1000, and 1100℃ for up to 200 h. X-ray diffraction and scanning electron microscopy with energy-dispersive X-ray spectroscopy were applied to study the oxidation behavior. The weight gain of the high Hf nickel-based superalloy exhibited a parabolalike curve, and no spallation of the oxide scale was observed during the oxidation tests. The alloy presented excellent oxidation resistance, and no HfO2 was observed in the oxide scale at 900℃. With the increase of the oxidation temperature to 1000℃, HfO2 particles formed in the spinel phases of the scale, and "peg-like" HfO2 was observed within and beneath the inner layer of Al2O3 after 200h. As the oxidation temperature rose to 1100℃, "peg-like" HfO2 was observed at the early stage of the oxidation test(within 25 h). The formation mechanism of HfO2 and its impact on oxidation resistance were investigated based on the analysis of the oxidation test results at different temperatures.

• 单位
  中国科学技术大学