A novel high-Cr CoNi-based superalloy with superior high-temperature microstructural stability, oxidation resistance and mechanical properties  

作　　者：Xiaorui Zhang Min Zou Song Lu Longfei Li Xiaoli Zhuang Qiang Feng 

机构地区：[1]Beijing Advanced Innovation Center for Materials Genome Engineering,State Key Laboratory for Advanced Metals,University of Science and Technology Beijing,Beijing 100083,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2024年第6期1373-1381,共9页矿物冶金与材料学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.52331005,52201100,52171095,and 92060113);the China Postdoctoral Science Foundation(No.2022M710346);Science and Technology on Advanced High Temperature Structural Materials Laboratory,China(No.6142903210207);the Fundamental Research Funds for the Central Universities,China(No.FRF-GF-20-30B);the National Key Research and Development Program of China(No.2017YFB0702902).

摘　　要：A novel multicomponent high-Cr CoNi-based superalloy with superior comprehensive performance was prepared,and the evaluation of its high-temperature microstructural stability,oxidation resistance,and mechanical properties was conducted mainly using its cast polycrystalline alloy.The results disclosed that the morphology of theγ′phase remained stable,and the coarsening rate was slow during the long-term aging at 900–1000℃.The activation energy forγ′precipitate coarsening of alloy 9CoNi-Cr was(402±51)kJ/mol,which is higher compared with those of CMSX-4 and some other Ni-based and Co-based superalloys.Importantly,there was no indica-tion of the formation of topologically close-packed phases during this process.All these factors demonstrated the superior microstructural stability of the alloy.The mass gain of alloy 9CoNi-Cr was 0.6 mg/cm^(2) after oxidation at 1000℃ for 100 h,and the oxidation resistance was comparable to advanced Ni-based superalloys CMSX-4,which can be attributed to the formation of a continuous Al_(2)O_(3) protective layer.Moreover,the compressive yield strength of this cast polycrystalline alloy at high temperatures is clearly higher than that of the conventional Ni-based cast superalloy and the compressive minimum creep rate at 950℃ is comparable to that of the conventional Ni-based cast superalloy,demonstrating the alloy’s good mechanical properties at high temperature.This is partially because high Cr is bene-ficial in improving theγandγ′phase strengths of alloy 9CoNi-Cr.

关 键 词：CoNi-based superalloys microstructure COARSENING OXIDATION mechanical properties 

分 类 号：TG132.3[一般工业技术—材料科学与工程]