摘要
在第二代镍基单晶高温合金中复合添加Y-La,经定向凝固后得到5.26×10–4%(质量分数)Y+6.05×10–4%La和47.64×10–4%Y+69.09×10–4%La的两种Y-La含量合金铸件,研究Y-La对合金定向凝固过程中合金熔体与Al2O3基陶瓷间的界面反应行为以及合金在1100℃下循环氧化时抗氧化性能的影响。采用扫描电子显微镜、能谱仪和X射线衍射仪等研究合金熔体与陶瓷材料间的界面组织形貌及界面反应产物成分以及循环氧化后合金表面氧化物的组织形貌、元素组成和相关物相。结果表明:Y-La含量增加会促进合金熔体与陶瓷间的界面反应,使得界面反应层更厚,更复杂;反应产物主要是含Y、La的氧化物;Y-La添加明显提高了合金的抗氧化性能,减少合金表面氧化膜的剥落;但Y-La过量会恶化合金的抗氧化性能,加快合金的氧化增重速率;合金表面氧化膜剥落痕迹明显,孔洞较多且内氧化严重。
Y-La was added into the second generation of nickel base single crystal superalloy and two kinds of alloy castings with Y-La content of 5.26 x 10 %（mass fraction, ） Y ＋ 6.05 x 10^-4% La and 47.64 x 10^-4% y ＋ 69.09 x 10^-4% La were obtained after directional solidification. The effect of Y-La content on the interface reaction between alloy melts mid A1203 based ceramics during directional solidification was investigated. The effect of alloy content on oxidation resistance of alloy at 1100 ℃ under cyclic oxidation was studied. The microstructure at the interface between alloy and mould, as well as file surface cross-section and fracture morphologies of the specimens, was characterized by means of scanning electron microscope （SME） with an energy-dispersive spectroscopy attachment. The phases of the oxides were identified by X-ray diffraction. The results show that the increase of Y-La content promotes the interfacial reaction, which makes file reaction layer thicker and more complex. The main reaction products are oxides containing Y and La. The addition of Y-La obviously improves the oxidation resistance of the alloy and reduces the exfoliation of the oxide film on the surface of the alloy. However, excessive Y-La will deteriorate the oxidation resistance of the alloy, accelerate file oxidation weight gain rate of the alloy. And the oxide film of the alloy surface has obvious traces of exfoliation, more holes and serious internal oxidation.
作者
尚根峰
廖金发
汪航
SHANG Genfeng;LIAO Jinfa;WANG Hang(School of Materials Science and Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China;Institute of Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China)
出处
《航空材料学报》
EI
CAS
CSCD
北大核心
2018年第6期43-49,共7页
Journal of Aeronautical Materials
基金
国家自然科学基金资助项目(51401095
51761014)
江西省自然科学基金(20171BAB216004)
江西省科技厅留学归国人员扶助计划(20161BBH80030)
关键词
稀土元素
高温合金
界面反应
循环氧化
rare earth elements
Ni-based superalloys
interfacial reaction
cyclic oxidation
