摘要
采用X射线衍射(XRD),扫描电镜(SEM)及能谱(EDS)等方法研究了不同W含量的3种试验单晶高温合金在1100℃的恒温氧化行为。结果表明:8%W合金氧化增重最大,6%与7%W的增重量相当,3种合金氧化动力学曲线近似遵从抛物线规律。试验合金氧化100 h后氧化膜剥落严重,8%W含量试验合金表面氧化膜剥落较6%和7%W合金严重,氧化膜由3层构成:最外层主要为(Ni,Co)O;中间层主要为氧化物和尖晶石相;最内层是连续的A1_2O_3层。在合金基体形成了γ'贫化层。在本合金体系下,随W元素含量变化,改变了试验合金1100℃氧化机制,在合金设计时,兼顾合金高温强度与抗氧化性能,应选择W含量不超过7%为宜。
The isothermal oxidation behaviors of three kinds of experimental third generation single crystal superalloys with different tungsten contents were investigated at 1100 °C in air by X-ray diffraction（XRD）,scanning election microscopy（SEM） and energy disperse X-ray analysis（EDS）. The results show that three kinds of alloys approximately obey subparabolic rate law during oxidation at 1100 °C for 100 h. The mass gain of 8 wt% W-containing alloy is higher than that of 6 wt% and 7 wt% W-containing alloys. The oxide scale exposed at 1100 °C consists of three layers： an outer Ni（Co）O layer,an intermediate layer mainly composed of oxides and spinels,and an inner Al_2O_3 layer. The γ′-free layer is formed in the base alloy. In the current alloy system,the transition of oxidation mechanism happens with increasing W content at 1100 °C; therefore,it is found that the alloys with W content less than 7% exhibit relative balance between oxidation resistance and solution strength.
作者
王效光
李嘉荣
史振学
刘世忠
岳晓岱
Wang Xiaoguang Li Jiarong Shi Zhenxue Liu Shizhong Yue Xiaodai(Science and Technology on Advanced High Temperature Structural Materials Laboratory, Beijing Institute of Aeronautical Materials, Beijing 100095, China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2017年第9期2493-2498,共6页
Rare Metal Materials and Engineering
关键词
第三代单晶高温合金
抗氧化性能
钨
third generation single crystal superalloy
oxidation resistance
tungsten
