基于不同代次镍基单晶高温合金900℃下氧化行为对比的Re元素作用分析  

The Re Element Effect Analysis Based on Comparison of Oxidation Behaviors of Different Generation Nickel-based Single Crystal Superalloys at 900℃

作　　者：汪纯慧 陈艳辉[1] WANG Chunhui;CHEN Yanhui(Institute of Microstructure and Property of Advanced Materials,Beijing University of Technology,Beijing,100124 China)

机构地区：[1]北京工业大学固体微结构与性能研究所,北京100124

出　　处：《科技创新导报》2020年第26期49-57,共9页Science and Technology Innovation Herald

摘　　要：本文分别选用典型一代、二代、三代单晶镍基高温合金作为研究对象,研究其在900 oC恒温氧化下的氧化行为。通过X射线衍射(XRD),扫描电子显微镜(SEM)和能谱(EDAX)等手段对合金氧化产物,不同氧化阶段的形貌和化学成分变化进行研究。研究结果表明:第一代0Re高温合金的氧化层结构与第二代3Re高温合金、第三代7Re高温合金的氧化层结构不同,且其富Ti外氧化层易脱落,第二代3Re高温合金的氧化层表面最致密。第一代0Re高温合金中Ti/Al较高,Ti在氧化过程中快速扩散破坏Al2O3氧化层结构,γ'相中Ti/Al比更高更易氧化。第二代3Re高温合金中Re含量较低,氧化过程中产生的少量Re2O7挥发未能完全破坏Al2O3保护层。第三代7Re高温合金中Re/Al较高,大量易挥发性Re2O7引起Al2O3氧化层失效,γ相中Re/Al比更高更易发生氧化。在本文选用的三种合金中含Re量为3wt.%的第二代3Re高温合金的抗氧化性能表现较好。Oxidation behavior of three typical single crystal Ni-based superalloys from the f irst generation to the third generation were investigate under 900 oC.X-ray diffraction,scanning electron microcopy and Energy dispersive spectrum were used to study the oxidation production,the morphology and chemical composition variations at different oxidation stages.The results show that the structure of the oxide layer of the f irst generation 0Re a lloy is different from that of the second and third generation a lloys,and its Ti-rich outer oxide layer is easy to fall off,and the surface of the oxide layer of the second generation 3Re alloy is the densest.Ti/Al ratio is higher in the f irst-generation 0Re alloy.Ti diffuses rapidly during the oxidation process to destroy the Al2O3 oxide layer structure.The Ti/Al ratio in theγ'phase is higher and easier to oxidize.The second generation 3Re alloy has less Re content,and a small amount of Re2O7 volatilization generated during the oxidation process cannot destroy the Al2O3 protective layer.The amount of Re/Al ratio in t he t hird-generation 7Re alloy is relatively h igh.A large amount of volatile Re2O7 causes the Al2O3 oxide layer to fail.In theγphase,the Re/Al ratio is higher and it is more prone to oxidation.Among the three alloys selected in this paper,the second generation nickel-based single crystal superalloys with a Re content of 3wt.%perform well in oxidation resistance.

关 键 词：镍基单晶高温合金 含铼量 900℃高温氧化行为 对比分析 

分 类 号：TG172.3[金属学及工艺—金属表面处理]