摘要
MCrAlY黏结层材料的相组织及性能对提高涡轮叶片热障涂层服役稳定性和使用寿命至关重要。采用Thermo-Calc热力学计算软件、X射线衍射仪、场发射扫描电镜、透射电镜、热膨胀仪等研究了Re改性NiCoCrAlY黏结层合金的组织特征、热膨胀性和抗高温氧化性。结果表明:改性黏结层合金以β-NiAl相为主还有少量σ-CoCr、α-Cr、Ni_(5)Y相,稀土元素Y与Ni结合形成Ni_(5)Y,改性元素Re则主要固溶于α-Cr和σ-CoCr相。当温度由室温升高到1200℃时,改性黏结层合金的热膨胀系数为(18.1±0.1)×10^(-6) K^(-1)。当1100℃等温氧化时间达到100 h,氧化膜和贫铝层厚度分别为(2.44±0.09)μm和(2.53±0.33)μm,氧化速率为(0.06±0.01)g·m^(-2)·h^(-1),达到完全抗氧化级对氧化速率的要求。与常规MCrAlY黏结层合金相比,1200℃热膨胀系数减小了12%,1100℃氧化100 h的增重速率降低了25%,即Re改性NiCoCrAlY黏结层合金具有更低的热膨胀性和更高的抗氧化性,能够为高性能MCrAlY黏结层材料的研制提供设计思路。
The phase constitution and properties of MCrAlY bond coating material are essential to improve the service stability and life of thermal barrier coatings for turbine blades.In this work,the microstructure characteristics,thermal expansion and high-temperature oxidation resistance of the Re-modified NiCoCrAlY bond coating alloy are systematically investigated using Thermo-Calc software,X-ray diffraction,field emission scanning electron microscopy,transmission electron microscopy,and thermal dilatometer,etc.The results show that the microstructure is primarily composed of β-NiAl coupled with someσ-CoCr,α-Cr and Ni_(5)Y.Meanwhile,the rare earth element Y binding Ni forms Ni_(5)Y,while the modification element Re is mostly solid dissolved in the α-Cr and σ-CoCr phases.Moreover,when the temperature increases from room temperature to 1200℃,the coefficient of thermal expansion reaches(18.1±0.1)×10^(-6) K^(-1).As the isothermal oxidation time at 1100℃extends to 100 h,the thickness of the oxidation layer and Al depletion layer is(2.44±0.09)μm and(2.53±0.33)μm,respectively.The oxidation rate is(0.06±0.01)g·m^(-2)·h^(-1),achieving the oxidation rate of a complete antioxidant level.Compared with the properties of the conventional MCrAlY bond coating alloy, the coefficient of thermal expansion at 1200 ℃ and the oxidation rate at 1100 ℃ for 100 h decrease by 12% and 25%, respectively. Namely, the Re-modified NiCoCrAlY bond coating alloy processes lower thermal expansion and higher oxidation resistance, which can provide design strategy for developing a high-property bond coating material.
作者
常振东
张婧
辛文彬
牟仁德
宋希文
蔡妍
CHANG Zhendong;ZHANG Jing;XIN Wenbin;MU Rende;SONG Xiwen;CAI Yan(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;School of Rare Earth Industry(School of Rare Earth Engineering and Technology),Inner Mongolia University of Science and Technology,Baotou 014010,Inner Mongolia,China)
出处
《材料工程》
北大核心
2025年第6期35-43,共9页
Journal of Materials Engineering
基金
国家科技重大专项项目(J2019-Ⅶ-0010-0150)
中国航发北京航空材料研究院院基金(KJ42250521)
内蒙古自治区高等学校青年科技英才支持计划(NJYT24070)
中央引导地方科技发展资金项目(2023ZY0009)
内蒙古自治区教育厅一流学科科研专项项目(YLXKZX-NKD-050)
内蒙古自治区直属高校基本科研业务费(118)。
关键词
NiCoCrAlY黏结层合金
Re改性
热膨胀性
抗氧化性
NiCoCrAlY bond coating material
Re modification
thermal expansion
high-temperature oxidation resistance
