Acta Metallurgica Sinica (English Letters) ›› 2010, Vol. 23 ›› Issue (2): 147-153.DOI: 10.11890/1006-7191-102-147

• 研究论文 • 上一篇    下一篇

Thermo-mechanical fatigue behavior of nickel-base powder metallurgy superalloy FGH96 under tension-tension loading

顾玉丽   

  1. 北京航空材料研究院
  • 收稿日期:2009-10-12 修回日期:2010-01-13 出版日期:2010-04-25 发布日期:2010-04-08
  • 通讯作者: 顾玉丽

Thermo-mechanical fatigue behavior of nickel-base powder metallurgy superalloy FGH96 under tension-tension loading

Yuli GU, Yuhuai HE, Shiyu QU, Guodong ZHANG, Fei ZHENG and Chunhu TAO   

  1. Beijing Institute of Aeronautical Materials, Beijing 100095, China
  • Received:2009-10-12 Revised:2010-01-13 Online:2010-04-25 Published:2010-04-08
  • Contact: YuliGU

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摘要：

研究了粉末高温合金FGH96在550℃ -720℃的拉-拉载荷下的热机械疲劳行为。同相位下FGH96合金的断裂模式是沿晶，反相位下合金的断裂模式是穿晶类解理。在较低应变幅下，对于同相位或反相位试样，Al、Ti and Nb 在γ′ 相的含量是较高的，对于同相位试样，Al、Ti and Nb 的γ′/γ的比值也是较高的，这是与在较低应变幅下γ′尺寸较大相一致。点阵参数错配是负的并且在较低应变幅下它的绝对值较小，这是与γ′形貌的变化相关联的。在较低应变幅下，变形是由基体中的位错线和位错对主导，在较高应变幅下，变形是由γ′中的大量超点阵堆垛层错主导。

关键词: nickel-base superalloy, thermo-mechanical fatigue, elemental partitioning, γ&prime, size, dislocation （镍基高温合金, 热机械疲劳, 元素分配, γ′尺寸, 位错）

Abstract:

Thermo-mechanical fatigue (TMF) behavior of FGH96, a nickel-base powder metallurgy superalloy, has been studied under tension-tension loading at the temperature range from 550℃ to 720℃. The results show that TMF fracture mode is intergranular for the in-phase (IP), but transgranular cleavage-like for the out-of-phase (OP) samples. The total content of Al, Ti and Nb in the γ' phases for the IP or OP samples and the partitioning ratio of γ'/γ in these elements for the IP samples are relatively higher at the lower strain amplitude, which is consistent with the case of the γ' size that is larger at the lower strain amplitude, the lattice parameter misfit is negative and the absolute value is lower at the lower strain amplitude that is correlative with the change of the γ' morphology. The deformation at the lower strain amplitude is mainly dominated by the dislocation lines and dislocation pairs in the matrix channels, at the higher strain amplitude dominated by the large numbers of superlattice stacking faults within the γ' phases.

Key words: Nickel-base superalloy, Thermo-mechanical fatigue, Elemental partitioning, γ' size, Dislocation