基于微束X射线荧光光谱的单晶叶片枝晶成分分布定量统计研究  

Quantitative Statistical Study on Dendritic Component Distribution of Single Crystal Blade Based on Microbeam X-Ray Fluorescence Spectroscopy

作　　者：周晴晴 李冬玲 蒋立武[1,3] 万卫浩 曾强 薛鑫[4] 王海舟[1,2] ZHOU Qing-qing;LI Dong-ling;JIANG Li-wu;WAN Wei-hao;ZENG Qiang;XUE Xin;WANG Hai-zhou(The NCS Testing Technology Co.,Ltd.,Beijing 100081,China;Central Iron and Steel Research Institute,Beijing 100081,China;University of Science and Technology Beijing,Beijing 100083,China;High Temperature Materials Research Department,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]钢研纳克检测技术股份有限公司,北京100081 [2]钢铁研究总院有限公司,北京100081 [3]北京科技大学国家材料服役安全科学中心,北京100083 [4]钢铁研究总院高温材料研究所,北京100081

出　　处：《光谱学与光谱分析》2023年第7期2112-2118,共7页Spectroscopy and Spectral Analysis

基　　金：国家重点研发计划项目(2021YFB3702100)资助。

摘　　要：镍基单晶高温合金是含有10~15种元素的复杂合金,具备优良的高温强度和耐腐蚀性。目前,先进燃气涡轮发动机的涡轮部件几乎都采用空心结构的单晶叶片。叶片服役过程中要承受超过其熔化温度数百摄氏度的高温和巨大离心应力,是工况条件最为恶劣的航空零件,被誉为“工业王冠上的明珠”,研制发展更耐高温的叶片材料以及改进叶片的冷却技术是提高涡轮进口温度的关键手段。新一代的单晶叶片中添加大量难熔元素(如Ta,W和Re等)用来提高承温能力,但这些元素在凝固过程中存在严重的枝晶偏析,导致组织内成分分布不均匀。通常采用复杂的多级热处理来溶解非平衡组织,减小偏析。枝晶间成分的详细表征对优化热处理工艺和叶片设计具有重要的意义。微束X射线荧光光谱是一种无损检测技术,制样简单,无需镀导电膜,可对样品进行多元素同时检测,多用于生物和考古领域,定量表征成分复杂的金属材料存在一定困难,应用案例较少。单晶高温合金具有特殊的十字枝晶组织,尺寸约为几百微米,微束X射线荧光光谱可以满足单晶叶片枝晶成分的详细表征和大区域面积的成分分布定量统计需求。本实验基于微束X射线荧光光谱技术,建立了镍基单晶高温合金枝晶成分定量统计分布表征方法,并应用于新型单晶涡轮叶片的全域枝晶组织成分定量分布表征,探讨了单晶涡轮叶片叶冠到榫头的成分演变规律,获得了不同部位主元素的一次偏析比和二次偏析比。结果表明,Re,W和Ta元素偏析严重,随着叶片截面尺寸的增加及与冷却铜盘距离的增加,叶片叶冠到榫头各元素的偏析程度降低;Cr,Co和Mo元素偏析比接近于1,偏析变化不明显,分布较均匀。通过对单晶叶片枝晶成分的定量统计解析,获得了单晶叶片成分的演变规律,为叶片的设计和凝固工艺的改进提供数据支撑。Nickel base single crystal superalloy is a complex alloy containing 10~15 elements,with excellent high-temperature strength and corrosion resistance.Almost all turbine parts of advanced gas turbine engines use single crystal blades with hollow structures.During their service,they must bear high temperatures hundreds of degrees Celsius above their metal melting temperature and huge centrifugal tensile stress.They are aviation parts with the worst working conditions and are known as the“pearl on the crown”.The development of more high-temperature resistant blade materials and the improvement of blade cooling technology are key to improving the turbine gas temperature.Many dense refractory elements such as Ta,W and re are added to the new generation of single crystal blades to improve the temperature resistance.These elements have serious dendrite segregation during solidification,resulting in uneven distribution of components in the microstructure.Complex step-by-step heat treatment is usually used to dissolve the non-equilibrium structure and reduce segregation.The detailed characterization of dendrite composition is of great significance in optimizing heat treatment and blade design.Microbeam X-ray fluorescence spectroscopy is a nondestructive testing technology.It is simple to prepare samples without plating conductive film and can provide information on the distribution of deep components of samples.It can detect multiple elements simultaneously.It is mostly used in biological and archaeological fields.It is not easy to characterize metal materials with complex components quantitatively,and there are few application cases.Single crystal superalloy has a special cross-dendrite structure with a size of hundreds of microns.Microbeam X-ray fluorescence spectroscopy can meet the needs of detailed characterization of single crystal blade dendrite composition and quantitative statistics of composition distribution in a large area.The quantitative statistical distribution characterization method of dendrite composi

关 键 词：单晶高温合金 涡轮叶片 微束X射线荧光光谱 枝晶偏析 成分分布 

分 类 号：O657.3[理学—分析化学]