Effect of Hf and Ta on creep deformation behaviors of PM Ni-based superalloys  

Hf和Ta对镍基粉末高温合金蠕变变形行为的影响

作　　者：Hao-peng ZHANG Jia-ming BAI Xin-yu LI Xiao-kun LI Jian JIA Jian-tao LIU Yi-wen ZHANG 张浩鹏;白佳铭;李新宇;李晓鲲;贾建;刘建涛;张义文(钢铁研究总院高温材料研究所,北京100081;北京钢研高纳科技股份有限公司,北京100081;东北大学材料科学与工程学院,沈阳110819)

机构地区：[1]High Temperature Material Research Institute,Central Iron and Steel Research Institute,Beijing 100081,China [2]Gaona Aero Material Co.,Ltd.,Beijing 100081,China [3]School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China

出　　处：《Transactions of Nonferrous Metals Society of China》2025年第3期849-862,共14页中国有色金属学报(英文版)

基　　金：financially supported by the National Science and Technology Major Project of China(No.2017-Ⅵ-0008-0078)。

摘　　要：Four powder metallurgy(PM)Ni-based superalloys with different Hf and Ta contents were creep-tested at 650℃ and 970 MPa,700℃ and 770 MPa,and 750℃ and 580 MPa,respectively.The effect of Hf and Ta on creep deformation behaviors of the superalloys was studied from multiple scales by SEM,electron backscatter diffraction(EBSD),and aberration-corrected scanning transmission electron microscope(AC-STEM).The results showed that Hf and Ta suppressed the intergranular fracture and initiation of cracks during the acceleration creep stage,which prolonged the creep rupture time.Hf and Ta inhibited the stacking faults extending and the dislocation climbing and promoted the Suzuki segregation of W during the steady-state creep stage,which reduced the minimum creep rate and delayed the start time of the acceleration creep stage.The Suzuki segregation of Co,Cr,Mo,Ti,Nb,W,and Ta along stacking faults was observed after Hf and Ta addition,leading to the localized phase transformation in the γ′phase,and the stacking fault phase was chemically disordered.This study provided ideas for the composition design of novel PM Ni-based superalloys and theoretical foundations for the combined addition of Hf and Ta.对4种不同Hf和Ta含量的镍基粉末高温合金分别在650℃、970 MPa,700℃、770 MPa和750℃、580 MPa下进行蠕变试验。采用扫描电子显微镜、电子背散射衍射和球差校正扫描透射电子显微镜研究Hf和Ta对该合金蠕变变形行为的影响。结果表明,Hf和Ta在加速蠕变阶段抑制了沿晶断裂和裂纹萌生,从而延长了蠕变断裂时间。Hf和Ta在稳态蠕变阶段抑制了层错扩展和位错攀移,促进了W的铃木偏聚,从而降低了最小蠕变速率和推迟了加速蠕变阶段的开始时间。添加Hf和Ta后,观察到Co、Cr、Mo、Ti、Nb、W和Ta沿层错的铃木偏聚,这导致γ′相中发生微区相变,而且层错相是化学无序的。本研究为新型镍基粉末高温合金的成分设计提供了思路,为Hf和Ta的共同添加提供了理论依据。

关 键 词：PM Ni-based superalloy HF TA creep deformation behaviors Suzuki segregation 

分 类 号：TG1[金属学及工艺—金属学]