Effect of Mo : W ratio on segregation behavior and creep strength of nickel-based single crystal superalloys

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

3 Scopus Citations
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Author(s)

  • Longfei Zhang
  • Zaiwang Huang
  • Liang Jiang
  • Junhua Luan
  • Zengbao Jiao

Detail(s)

Original languageEnglish
Pages (from-to)481-489
Journal / PublicationMaterials Science and Engineering A
Volume744
Online published13 Dec 2018
Publication statusPublished - 28 Jan 2019

Abstract

In past decades, molybdenum (Mo) has demonstrated the potential to replace tungsten (W) in designing lighter nickel-based single crystal superalloys with enhanced creep resistance. In this research, three groups of nickel-based single crystal superalloys are designed and prepared by tuning the Mo:W ratio. The experimental observations show that the primary and secondary dendrite arm spacings are both independent on Mo:W ratio, but the γ/γ′ eutectic volume fraction decreases as Mo:W ratio increases. The electron probe microanalysis reveals that Re, W and Co segregate to dendrite core regions, while Al, Ti, Cr, Mo and Ta to interdendritic regions. The microsegregation of Ta, W and Re are gradually relieved with increasing Mo:W ratio. Atom probe tomography results further indicate that Cr and Mo are depleted in γ/γ′ eutectics, leading to the enrichment of Cr and Mo at interdendritic regions away from γ/γ′ eutectics. Creep rupture results show that the rupture life at 1040 °C/145 MPa is improved as Mo:W ratio increases.

Research Area(s)

  • Alloy design, Creep rupture, Microsegregation, Mo:W ratio, Nickel-based single crystal superalloys, γ/γ′ eutectic

Citation Format(s)