摘要
为研究高代单晶高温合金组织稳定性影响机制,制备含6%(质量分数,下同)Ru和4.5%Ru的两种单晶高温合金D1和D2,经完全热处理后在980℃下长期时效1000 h。观察不同尺度上的显微组织及合金元素分布,并结合热力学计算进行分析。结果表明:两种合金经完全热处理后仍有较高含量的高熔点合金元素偏析于枝晶干中,使枝晶干区域长期时效后均有较多TCP相析出;两种合金中,Ru和Re均为TCP相主要形成元素,Ru含量较高的D1合金中TCP相析出量多于Ru含量较低的D2合金;Ru和Re含量增加会使合金平均d轨道电子能级增大,增加合金TCP相析出倾向,但由于Ru可以降低Re在γ相中偏析程度,因此Ru含量增加又可以减少Re对合金组织稳定性的不良影响;在本研究中,Ru对TCP相析出的促进更为显著,因此,在980℃下长期时效1000 h后D1合金较D2合金析出更多TCP相。
In order to study the influence mechanisms of microstructure stability of high generation single crystal superalloys,the D1 and D2 alloys which contain 6%(mass fraction)Ru and 4.5% Ru respectively were prepared after complete heat treatment and long-term aging at 980℃ for 1000 h.The microstructure and alloying element distribution at different scales were examined and the results were analyzed combining with thermodynamic calculation.The results show that there are still high content of refractory elements segregating in the dendrite region after complete heat treatment,inducing to TCP precipitation in the dendrite after long-term aging.Ru and Re are the main forming elements of TCP in both D1 and D2 alloys,and more TCP phase precipitates in D1 alloy which contains more Ru than in D2 alloy.Because both Ru and Re can increase the d-orbital energy level of single crystal superalloy,higher Ru and Re content leads to more TCP phase precipitation.However,since Ru can reduce the segregation degree of Re inγphase,the increase of Ru content can reduce the adverse effect of Re on the microstructure stability of single crystal superalloy.In this study,Ru plays a more significant role in promoting TCP phase precipitation,leading to more TCP phase precipitating in D1 alloy than in D2 alloy after long-term aging at 980℃ for 1000 h.
作者
岳晓岱
李嘉荣
刘世忠
史振学
王效光
董建民
YUE Xiao-dai;LI Jia-rong;LIU Shi-zhong;SHI Zhen-xue;WANG Xiao-guang;DONG Jian-min(Science and Technology on Advanced High Temperature Structural Materials Laboratory,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2021年第4期63-70,共8页
Journal of Materials Engineering
基金
国家重点研发计划项目(2017YFB0701503)
航空动力基金项目(6141B090554)
中国航发自主创新专项资金项目(ZZCX-2019-013)。
关键词
单晶高温合金
钌
铼
TCP相
协同作用
single crystal superalloy
ruthenium
rhenium
TCP phase
synergistic effect
