J. Mater. Sci. Technol. ›› 2018, Vol. 34 ›› Issue (5): 806-810.DOI: 10.1016/j.jmst.2017.04.009

• Orginal Article • Previous Articles     Next Articles

Intergrowth of C phase within μ phase in a Re-containing Ni-base single crystal superalloy

Shuang Gaoab, Yizhou Zhoua(), Zhi-Quan Liua(), Tao Jina   

  1. aInstitute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
    bDivision of Energy and Environment, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
  • Received:2016-11-21 Revised:2016-12-24 Accepted:2016-12-28 Online:2018-05-10 Published:2018-05-04

Abstract:

Precipitation of topologically close-packed phases in a Re-containing Ni-base single crystal superalloy was studied under elevated temperature by in situ transmission electron microscopy. Above 1150 °C, a new intergrowth structure called C phase was found within μ phase with a defined crystallographic orientation relationship. Elements mapping analysis reveals that C phase has a similar element composition as μ phase, but contains a lower level of Cr, W and Re. With increasing temperature, the proportion of C phase increases gradually. At 1250 °C, C phase becomes the dominant precipitate. It is demonstrated that C phase is more thermodynamically stable than μ phase above 1150 °C that leads to an intergrowth pathway from μ phase to C phase.

Key words: Ni-base superalloy, Phase transformation, Precipitation