高W高Ta型粉末高温合金的蠕变性能及溶质原子偏聚  

Creep Properties and Solute Atomic Segregation of High-W and High-Ta Type Powder Metallurgy Superalloy

作　　者：白佳铭 刘建涛[1,2] 贾建 张义文[1,2] BAI Jiaming;LIU Jiantao;JIA Jian;ZHANG Yiwen(High Temperature Material Research Institute,Central Iron and Steel Research Institute,Beijing 100081,China;Gaona Aero Material Co.Ltd.,Beijing 100081,China;School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China)

机构地区：[1]钢铁研究总院高温材料研究所,北京100081 [2]北京钢研高纳科技股份有限公司,北京100081 [3]东北大学材料科学与工程学院,沈阳110819

出　　处：《金属学报》2023年第9期1230-1242,共13页Acta Metallurgica Sinica

基　　金：国家科技重大专项项目No.2017-VI-0008-0078。

摘　　要：研究了最新开发的高W高Ta型粉末高温合金GNPM01优异的蠕变性能和蠕变强化机理。利用球差校正扫描透射电子显微镜(AC-STEM),详细分析了粉末高温合金GNPM01蠕变变形机制和溶质原子在超点阵层错和微孪晶上的偏聚行为,阐明了溶质原子Cr、Co、Mo的偏聚是导致无序微孪晶在晶内扩展的根本原因。GNPM01合金在815℃蠕变过程中,γ’相内孤立的超点阵外禀层错(SESF)处出现了W、Ta、Nb、Co和Ti的Suzuki偏聚,并且偏聚原子具有有序的占位,造成SESF处发生局部微区相变(LPT),形成的[(Ni,Co)_(3)(Ti,Nb,Ta,W)]有序相η相能有效阻碍微孪晶的形成和扩展,从而降低合金的蠕变速率。Developing superalloys and improving their temperature capability are extremely crucial for the advancement of aero-engines.The powder metallurgy(PM) technology can prevent the macroscopic segregation caused by casting and create a high-alloying aero-engine turbine disk alloy having remarkable microstructural homogeneity and superior thermal capability.PM superalloys have been developed into the 3rd generation alloys for decades,and alloys such as René 104 already entered service.The chemical composition of the 4th generation PM superalloy is still being researched with the aim of increasing the temperature capability for disk applications to 815oC.In this work,the remarkable creep resistance and creep strengthening mechanism of a novel high-W and high-Ta type PM superalloy GNPM01 was examined.The creep deformation mechanism of GNPM01 alloy and the segregation of elements on deformation defects were investigated using advanced spherical aberration-corrected scanning transmission electron microscopy.The results reveal that the creep resistance of GNPM01 alloy is considerably higher than that of the 3rd generation PM superalloy.The temperature capacity of GNPM01 alloy is approximately 40oC greater than that of FGH4098 alloy under the creep condition of 600 MPa and 1000 h.The creep strength of GNPM01 alloy is approximately 160 MPa higher than that of the FGH4098alloy at 815℃.In the experimental conditions,the creep deformation behavior was dominated by deformed microtwins,and the GNPM01 alloy clearly slowed down the widening of extended stacking faults and the thickening of microtwins during the creep deformation.It was discovered that the element enrichment of Co,Cr,and Mo existed in the microtwins,and the phase transformation of the twin-structure in γ'phase was disordered because of the segregation of Co,Cr,and Mo by atomic-level energy dispersive Xray spectroscopy.The isolated superlattice stacking faults in FGH4098 alloy also occurred in the disordered phase transitions.The disordering of superlattice stack

关 键 词：粉末高温合金 W TA 蠕变机制 局部微区相变 微孪晶 

分 类 号：TG123.3[金属学及工艺—金属学]