摘要
采用扩散共渗方法在TiAl合金表面制备了Si-Co-Y渗层,分析了渗层的组织结构、形成机制及其在950℃时的抗氧化性能。结果表明,所制备的Si-Co-Y渗层组织致密,呈多层结构:主要由TiSi_(2)表层,TiSi_(2)+Ti_(5)Si_(4)+Ti_(5)Si_(3)混合组成的外层,Ti_(5)Si_(3)中间层和TiAl_(2)内层组成;渗层生长过程由Si的向内扩散控制,且遵循先沉积Si后沉积Co、Y的有序过程。氧化试验结果表明,Si-Co-Y渗层具有良好的高温抗氧化性能,在950℃氧化100 h后表面形成了由SiO_(2)、TiO_(2)和Al_(2)O_(3)组成的保护性氧化膜;该氧化膜的生长遵循抛物线规律,氧化增重的抛物线速率常数约为6.3×10^(-2)mg^(2)·(cm^(4)·h^(1/2))^(-1),较基体合金低约1个数量级。
Si-Co-Y co-deposited coating was prepared on the surface of TiAl alloy by pack cementation process.The microstructure,formation mechanisms,and oxidation performance of the coating at 950ºC were analyzed.Results show that the obtained Si-Co-Y co-deposited coating is compact and possesses multilayer structure:it is mainly composed of TiSi_(2)superficial zone,TiSi_(2)and Ti_(5)Si_(4)mixed outer layer,Ti_(5)Si_(3)middle layer,and TiAl_(2)inner layer.The growth of Si-Co-Y co-deposited coating is controlled by inward diffusion of Si,which follows an orderly deposition process of Si,and then Co and Y atoms.High-temperature oxidation tests show that the Si-Co-Y co-deposited coating has good oxidation resistance,which is attributed to the formation of a protective oxide scale consisting of SiO_(2),TiO_(2),and Al_(2)O_(3).The growth of the oxide scale on the coating follows a parabolic law,and the parabolic rate constant of oxidation mass gain is about 6.3×10-2 mg2·(cm4·h1/2)-1,which is lower than that of the TiAl substrate by about one order of magnitude.
作者
吕威
李轩
位泽坤
谢小青
贾丽娜
来升
Lv Wei;Li Xuan;Wei Zekun;Xie Xiaoqing;Jia Lina;Lai Sheng(College of Mechanical Engineering,Sichuan University of Science and Engineering,Zigong 643000,China;Key Laboratory of Mechanical Structure Optimization&Material Application Technology,Luzhou 646000,China;Sichuan Vocational College of Chemical Industry,Luzhou 646000,China;Beihang University,Beijing 100191,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2023年第12期4276-4283,共8页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51961003)
四川省科技厅重点研发项目(2022YFSY0036)
机械结构优化及材料应用泸州市重点实验室开放课题(SCHYZSA-2022-01,SCHYZSB-2022-01,SCHYZSB-2022-02)
四川轻化工大学研究生创新基金(y2022043)
智能制造泸州市重点实验室开放基金(ZZ202204)。
