Effects of Nb and W additions on the microstructures and mechanical properties of novel γ/γ’ Co-V-Ti-based superalloys

Xingjun Liu, Yunwei Pan, Yuechao Chen, Jiajia Han, Shuiyuan Yang, Jingjing Ruan, Cuiping Wang, Yuansheng Yang, Yingju Li

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)

Abstract

Microstructures, elemental partition behavior, phase stabilities and mechanical properties of Nb-and W-containing Co-V-Ti-based superalloys were investigated. Elemental partition coefficients (KX = Cγ’/Cγ ) of Nb and W in Co-V-Ti-based superalloys are 2.07 and 1.10, respectively. The γ’ solvus temperatures are determined as 1023 °C, 1055 °C and 1035 °C in Co-12V-4Ti, Co-10V-4Ti-2Nb and Co-10V-4Ti-2W alloys, which are higher than those of Co-9Al-9W alloy (1000 °C). The mass densities of quaternary Co-10V-4Ti-2Nb and Co-10V-4Ti-2W alloys are about 8.31 and 8.50 g·cm−3, respectively, which are 15% lower than Co-Al-W-based superalloys (9.8 g·cm−3 ). All examined alloys exhibit an anomalous positive dependence on temperature rising from 600 to 750 °C. Strengths of all examined alloys are higher than those of MarM509 (traditional Cobalt-based superalloy) and Co-9Al-9W at all temperatures that we investigated. The maximum flow stress of Co-V-Ti-Nb alloy is about 638 MPa at 750 °C while that of Co-V-Ti-W alloy is about 588 MPa at 700 °C.

Original languageEnglish
Article number563
JournalMetals
Volume8
Issue number7
DOIs
Publication statusPublished - 2018 Jul 23
Externally publishedYes

Keywords

  • Cobalt-based superalloys
  • Gamma prime
  • High-temperature mechanical properties
  • Microstructure evolution

ASJC Scopus subject areas

  • Materials Science(all)

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