定向凝固合金涡轮叶片服役后组织研究

Microstructure damage of directionally solidified alloy turbine blade after service

涡轮叶片是飞机发动机中服役条件最为苛刻的部件,其性能关系到发动机的工作安全。因叶片服役环境复杂,服役条件苛刻,在服役中不可避免地形成各类损伤,对其服役损伤进行研究,有着重要的工程意义和经济意义。本工作选用实际服役后的定向凝固合金涡轮叶片作为研究对象,截取叶身上部高度80%横截面位置,利用SEM和EDS分析等方法进行定性和定量的微观组织分析。结果显示:该叶片存在两种不同类型的γ'相。一类γ'相尺寸小,形状规则,另一类γ'相尺寸大,形状不规则;借助对各部位γ'相进行尺寸分布表征,结合截面各部位硬度测试分析,表征了叶片不同部位间的微观损伤程度。结果表明,不同部位的服役工况不同,微观组织损伤程度不同。此外,总结和分析了在叶片个别部位出现的基体裂纹和涂层损伤等情况。

Turbine blades are the most demanding components in aircraft engines,and their performance is related to the safety of the whole engine.Due to the complex service environment and harsh service conditions of blades,various types of damage cannot be prevented in service.Therefore,it is of great engineering and economic significance to study the service damage of blades.In this paper,the directional solidification alloy turbine blade after actual service was selected as the research object.The cross section position of 80%upper height of the blade was intercepted,and the qualitative and quantitative microstructure analysis was carried out by SEM and EDS analysis.The results show that there are two different types ofγ'phases in this leaf.One kind ofγ'phase has small size and regular shape,the other has large size and irregular shape.The degree of microscopic damage among different parts of the blade is characterized with the help of dimensional distribution characterization of theγ'phase of each part,combined with the analysis of hardness testing of each part of the cross-section.The results show that the service conditions of different parts are different,and the degree of microstructure damage is different.In addition,matrix crack and coating crack in some parts of blade are summarized and analyzed.