航空材料学报2025，Vol.45Issue(5)：142-149,8.DOI:10.11868/j.issn.1005-5053.2025.000116
P对定向凝固高温合金DZ125组织和性能的影响
Effects of P on microstructures and properties of directionally solidified superalloy DZ125
摘要
Abstract
The directionally solidified superalloy DZ125 is widely used as turbine blades in aero-engines.This work investigates the influence of phosphorus(P)on the microstructure,mechanical properties and crack susceptibility of DZ125 alloy.The results indicate that P primarily segregates at grain boundaries in DZ125 alloy and has little effect on γ′phases,γ+γ′eutectic and carbides in the alloy.When P content reaches 0.008%(mass fraction,the same below)P-rich phases form in the interdendritic regions during casting,which subsequently dissolve back into the matrix during heat treatment.When the P content is no more than 0.0039%,P shows no obvious effects on the room-temperature tensile properties or the stress rupture life at 980℃/235 MPa.However,it has a significant impact on the stress rupture life at 760℃/805 MPa:the alloy with 0.0039%P exhibits a 37%decrease in stress rupture life at 760℃/805 MPa compared to the alloy with 0.0013%P,due to the segregation of P at grain boundaries weakens the grain boundaries.When the P content reaches 0.011%,the intergranular cracks appear in the DZ125 alloy hollow turbine blades during directionally solidified process.The main reason for the increase of crack susceptibility is excessive enrichment of P at grain boundaries and precipitation of P-rich phases nearby grain boundaries,which leads to grain boundary weakening and crack initiation.关键词
P元素/DZ125合金/微观组织/力学性能/裂纹倾向性Key words
P element/DZ125 alloy/microstructure/mechanical property/crack susceptibility分类
矿业与冶金引用本文复制引用
宋尽霞,姜驰航,康永旺,肖程波,蒋立武,李明,戴圣龙..P对定向凝固高温合金DZ125组织和性能的影响[J].航空材料学报,2025,45(5):142-149,8.基金项目
国家重点研发计划项目(2022YFB3705004) （2022YFB3705004）
