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 René104 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 815^oC. 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 40^oC 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 FGH4098 alloy at 815^oC. 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 X-ray spectroscopy. The isolated superlattice stacking faults in FGH4098 alloy also occurred in the disordered phase transitions. The disordering of superlattice stacking fault or microtwin structure was due to the segregation of Cr, Co, and Mo, which also resulted in the a / 6<112> Shockley partials shearing γ′ phase without producing high-energy nearest-neighbor Al—Al bonds. The segregation disordered the L1₂ structure resulted in reduced pinning of partials by the ordered γ′ phase, which increased the creep rate of the alloy. During the GNPM01 alloy creeping at 815^oC, solute atoms W, Ta, and Nb segregated at the isolated superlattice extrinsic stacking fault (SESF) had ordered atomic occupancy. The fault-level local phase transformation occurred in isolated SESF, forming the [(Ni, Co)₃(Ti, Nb, Ta, W)] ordered η phase that can effectively inhibit the formation and expansion of microtwins, thus lowering the creep rate of GNPM01 alloy.