摘要
利用热重分析法及X射线衍射(XRD)、扫描电镜(SEM/EDX)等手段,研究一种镍基高温合金在850℃和950℃的高温氧化行为.结果表明,氧化动力学曲线遵循抛物线规律,随着氧化时间的延长,氧化增重变得缓慢.在850℃和950℃时氧化膜由三层组成,外层为复杂氧化物和尖晶石化合物等,中间过渡层和内氧化层均为Al_2O_3.氧化过程中,外层中形成的富Ia相抑制基体合金中Al向外扩散,形成了平直连续Al_2O_3的中间层,使氧化速度减慢,进而抑制氧化膜生长,降低氧化速率.
The high temperature oxidation behavior of a new nickel-based superalloy was investigated at 850℃ and 950 ℃ in air by means of TGA, XRD and SEM/EDX. The results show that oxidation kinetics basically obeys parabolic law. The formed oxide scale is consisted of three layers at 850 ℃ and 950℃.The outer layer is mainly composed of complex oxides and spinals, and the middle one is a continuous layer and finally the inner one is a dis-continuous layer of Al2O3. The out layer is rich in Ta, which may suppress the diffusion rate of AI. As a result, a continuous oxide layer of Al2O3 is formed in the middle of the scale to restrain the growth of oxide scale and decrease the oxidation rate.
出处
《腐蚀科学与防护技术》
CAS
CSCD
北大核心
2011年第4期298-302,共5页
Corrosion Science and Protection Technology
基金
国家自然科学基金项目(50571070)资助
关键词
镍基合金
高温氧化
氧化动力学
Ni-based superalloy
high temperature oxidation
oxidation kinetics
