J. Mater. Sci. Technol. ›› 2011, Vol. 27 ›› Issue (5): 437-442.

• Reviews • 上一篇    下一篇

Microstructure and Elevated Temperature Tensile Behavior of Directionally Solidified Ni-rich NiAl-Mo(Hf) Alloy

韩萍   

  1. 渤海大学
  • 收稿日期:2010-11-30 修回日期:2011-01-19 出版日期:2011-05-28 发布日期:2011-05-28
  • 通讯作者: 韩萍
  • 基金资助:

    高温度梯度定向凝固技术制备NiAl基多相合金的研究;定向凝固NiAl基共晶合金的超塑性及其变形机理的研究

Microstructure and Elevated Temperature Tensile Behavior of Directionally Solidified Ni-rich NiAl-Mo(Hf) Alloy

Ping Han1), Yihui Qi2), Jianting Guo2)   

  1. 1) Department of Physics, Bohai University, Jinzhou 121013, China
    2) Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:2010-11-30 Revised:2011-01-19 Online:2011-05-28 Published:2011-05-28
  • Contact: Ping Han
  • Supported by:

    the Dr. Start Fund of Liaoning Science and Technology Agency (No. 20021071) and the Program of the Innovation Team of Liaoning Office of Education (No. 2006T078)

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摘要： The microstructure, high strain rate superplasticity and tensile creep behavior of DS NiAl-Mo(Hf ) alloy have been investigated. The alloy exhibits dendritic structure, in which dendritic arm is NiAl phase, interdendritic region is Ni3Al phase, and Mo-rich phase distributes in the NiAl and Ni3Al phases. The alloy exhibits high strain rate superplastic deformation behavior, and the maxium elongation is 104% at 1373K and strain rate of 1.04×10-2s-1. The balance between strain hardening (by dislocation glide) and strain softening (by dynamic recovery and recrystallization) is responsible for the superplastic deformation. All the creep curves of the DS NiAl-Mo(Hf) alloy have similar shape of a short primary creep and dominant steady creep stages, and the creep strain is great. The possible creep deformation mechanism was also discussed. The creep fracture data follow the Monkman-Grant relationship.

Abstract: The microstructure, high strain rate superplasticity and tensile creep behavior of directionally solidified (DS) NiAl-Mo(Hf) alloy have been investigated. The alloy exhibits dendritic structure, where dendritic arm is NiAl phase, interdendritic region is Ni3Al phase, and Mo-rich phase distributes in the NiAl and Ni3Al phases. The alloy exhibits high strain rate superplastic deformation behavior, and the maximum elongation is 104.2% at 1373 K and strain rate  of  1.04×10-2 s-1. The balance between strain hardening (by dislocation glide) and strain softening (by dynamic recovery and recrystallization) is responsible for the superplastic deformation. All the creep curves of the DS NiAl-Mo(Hf) alloy have similar shape of a short primary creep and dominant steady creep stages, and the creep strain is great. The possible creep deformation mechanism was also discussed. The creep fracture data follow the Monkman-Grant relationship.

Key words: NiAl alloy, Directional solidification, Superplasticity, Creep