摘要
采用X射线衍射(XRD)、扫描电镜(SEM)及能谱(EDAX)等手段,研究了一种高Cr镍基单晶高温合金在1 050℃的高温氧化行为。结果表明,氧化初期合金增重迅速,氧化增重不遵循抛物线规律,表面氧化膜出现剥落,氧化过程由形成Al2O3和Cr2O3所控制。高温氧化期间,合金发生明显的外氧化和内氧化,外氧化膜由Cr2O3和(Ni,Co)Cr2O4组成,内氧化物为Al2O3。在内氧化物上方出现贫Al富Ta区,元素贫化区尺寸随时间的延长而增大,富Ta相抑制基体中Al向外扩散,并抑制氧化膜生长。
The high temperature oxidation behavior of the single-crystal Ni-base superalloy with high Cr content was investigated at 1 050℃ in air by using of SEM, XRD and EDAX. The results show that the mass gain rapidly increases in the initial stage, and the kinetic curve of the alloy does not obey the parabolic law; a small amount of oxide scale spallation happens in the course of oxidation for 317 h and the oxidizing process is mainly controlled by the formation of Cr2O3 and Al2O3 phases. An obvious oxidation and internal oxidation occurs during oxidation at 1 050℃. The oxides in the outer layer consist of Cr203 and （Ni, Co）Cr2O4, while the internal oxide is Al2O3 only. The poor-aluminum but rich-tantalum areas appear above the internal oxides, the size of the poor-aluminum areas increases gradually as the oxidizing time prolongs. The tantalum-rich phase may restrain the Al in the matrix diffusing outward, which restrains the growth of the oxide scales.
出处
《铸造》
CAS
CSCD
北大核心
2011年第2期175-179,共5页
Foundry
关键词
镍基单晶合金
高温氧化
内氧化
single-crystal Ni-base superalloy
high temperature oxidation
internal oxidation
