摘要
采用光学显微镜(OM)、扫描电镜(SEM)、能谱仪(EDS)及差示扫描量热仪(DSC)研究了定位Pt丝对单晶高温合金空心叶片表层铸态组织、凝固特性及时效组织的影响。结果表明:定向凝固过程中,Pt丝被熔化在高温合金熔体中并导致芯撑处合金凝固偏析倾向增大。在1100℃不同时间的时效处理过程中,芯撑处有再结晶形成,时效时间超过500 h后,芯撑处γ′筏化严重,且有拓扑密堆积相(TCP相)析出。定向凝固过程中叶片与模壳之间非均衡收缩及模壳清理过程导致了芯撑变形并诱导时效过程中再结晶产生;长期时效时芯撑合金中富集的Pt导致其基体组织中W、Re等富集,促进了TCP相的析出,对应芯撑位置的叶片表层合金中Pt含量较低,无TCP相形成。
Effect of Pt pinning wires on as-cast microstructure,solidification characteristics and aging microstructure of surface layer of single crystal superalloy hollow turbine blades was studied using optical microscope(OM),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)analysis and differential scanning calorimetry(DSC).The results show that during the directional solidification process,Pt wires are melted in the superalloy melt,leading to an increased tendency for alloy solidification segregation at the pin.During the aging treatment at 1100℃for different time,recrystallization occurs at the pins.Theγ′phase rafting becomes more severe when the aging time exceeds 500 h,and the topologically closed phase(TCP)precipitates in the pins.During the directional solidification process,the non-equilibrium solidification shrinkage between the blades and the mold shell,as well as the cleaning process of the mold shell,lead to the deformation of the pin,thereby inducing recrystallization during the aging treatment.The enrichment of Pt in the pin alloy during long-term aging leads to the enrichment of W,Re,and other elements in its matrix structure,promoting the precipitation of TCP phase.Due to the low Pt content in the surface alloy of the turbine blade corresponding to the pins position,there is no TCP phase formed.
作者
姜卫国
董琳
李凯文
胡玉昆
张珊珊
JIANG Wei-guo;DONG Lin;LI Kai-wen;HU Yu-kun;ZHANG Shan-shan(School of Intelligent Manufacturing,Weifang University of Science and Technology,Shouguang 262700,China;Weifang Key Laboratory of High-temperature Materials and Single Crystal Components Fabrication Technology for Advanced Engine System,Shouguang 262700,China;Institute of Metal Research,Chinese Academy of Science,Shenyang 110016,China)
出处
《材料热处理学报》
CAS
CSCD
北大核心
2024年第8期108-117,共10页
Transactions of Materials and Heat Treatment
基金
山东省自然科学基金(ZR2022ME066)。
关键词
单晶高温合金
Pt丝
时效
再结晶
TCP相
single crystal superalloy
Pt wire
aging
recrystallization
TCP phase
