摘要
Silicon (Si) and reactive elements (REs) like hafnium (Hf) have favorable effects on improving the high-temperature oxidation resistance. To reveal the interaction effect between them, Si with different contents was added into P-NiAlHf alloy in this study. Cyclic oxidation behavior at 1200℃ was investigated. Results show that Si can increase the Hf-rich precipitates and suppress Hf outward diffusion, thus inhibit the RE effect leading to worse oxidation resistance. However, NiAlHf-5Si alloy exhibited a lower oxidation rate and better spallation resistance mainly because of the existence of micro-cracks and Ni2 Al3 phases which provided more rapid diffusion paths for Al^3+.
Silicon（Si） and reactive elements（REs） like hafnium（Hf） have favorable effects on improving the high-temperature oxidation resistance. To reveal the interaction effect between them, Si with different contents was added into β-Ni Al Hf alloy in this study. Cyclic oxidation behavior at 1200?C was investigated. Results show that Si can increase the Hf-rich precipitates and suppress Hf outward diffusion, thus inhibit the RE effect leading to worse oxidation resistance. However, Ni Al Hf-5 Si alloy exhibited a lower oxidation rate and better spallation resistance mainly because of the existence of micro-cracks and Ni2 Al3 phases which provided more rapid diffusion paths for Al3+.
基金
financially supported by the National Natural Science Foundation of China (No. 51425102)
the China Postdoctoral Science Foundation (Nos. 2017T100023 and 2016M600028)
