摘要
采用X射线衍射(XRD),扫描电镜(SEM)及能谱(EDX)等方法研究了不同钴含量的两种镍基单晶高温合金在900,1000和1100℃的恒温氧化行为。研究发现,增加合金中的Co含量,会降低合金的扩散激活能,引起氧化速率的略微增加。在900和1000℃氧化时符合抛物线规律,氧化膜分为3层:外层主要由Cr2O3和TiO2组成;中间层是很薄的CrTaO4和Ta2O5氧化层;内层是连续的Al2O3氧化层。在1100℃时氧化膜的严重剥落和CrO3的挥发使增重曲线略微偏离抛物线规律,生成了NiCr2O4,CoAl2O4,CoNiO2和Co2TiO4等尖晶石相,并发生了内氮化。
The isothermal oxidation behaviors of two kinds of single-crystal nickel-base superalloys DD10 with different cobalt contents were investigated at 900,1000 and 1100 ℃ in air by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and energy disperse X-ray analysis（EDX）.It is found that increasing the cobalt content can decrease the diffusion activity energy of the alloy and thus increase the oxidation rate slightly.For the oxidation at 900 ℃ and 1000 ℃,the mass gain basically obeys the parabola law.The oxide scales consist of three layers：an outer layer of Cr2O3 and TiO2,a thin intermediate layer of CrTaO4 and Ta2O5,and a continuous inner layer of Al2O3.For the oxidation at 1100 ℃,because of the severe spalling of the scale and the volatilization of the CrO3,the kinetics curves deviate from the parabolic law a little.Some spinels such as NiCr2O4,CoAl2O4,CoNiO2 and Co2TiO4 form and inner nitridation phenomenon happens.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2010年第8期1407-1410,共4页
Rare Metal Materials and Engineering
关键词
镍基高温合金DD10
单晶
氧化
nickel base superalloyDD10
single crystal
oxidation
