Development of low thermal expansion superalloy

  • K. Sato
  • T. Ohno
Technical Papers


Alloy 903 and Alloy 909 are well-known Fe-Co-Ni-Al-Ti-Nb alloys with controlled low thermal expan-sion, but they have some properties that can be improved. To improve stress-accelerated grain boundary oxidation embrittlement of Alloy 903 and instability of theγ phase of alloy 909, two new alloys with good stress-rupture ductility, high creep-rupture strength, high tensile strength at high temperature, and good controlled thermal expansion were developed. These property improvements were accomplished by the combination of optimizing the Fe-Co-Ni ratio of the matrix and stabilizing theγ phase with the addition of aluminum.


coefficient of thermal expansion Laves phases stress rupture superalloys 


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Copyright information

© ASM International 1993

Authors and Affiliations

  • K. Sato
    • 1
  • T. Ohno
    • 1
  1. 1.Metallurgical Research Laboratory, Yasugi Works. Hitachi Metals, Ltd.ShimaneJapan

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