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In order to determine the composition of the novel gamma' strengthened Co-Al-W-based wrought superalloy of the Co-Al-W-Ni-Ta-Ti system and the corresponding heat treatment process, using Pandat calculation software and the thermodynamic database of cobalt-based superalloys, the influence of alloying elements on the precipitation behavior of the equilibrium phase was calculated. The results show that W, Ni, Ta, and Ti can improve the stability of gamma', W, Ta can increase the precipitation tendency of the harmful phase chi-D0(19), and Ti and Ni can suppress the precipitation of the harmful chi-D0(19) phase and B2 phase, respectively. So the alloy composition is determined as Co-9Al-3W-30Ni-2Ta-3.5Ti (at%). The phase transition law of this alloy was calculated, and the results showed that the equilibrium precipitation phases of the alloy were y, gamma', gamma-D0(19) and Co7Ta2, and the initial precipitation temperatures were 1355, 1169, 700, and 288 degrees C, respectively. The alloy heat treatment process is determined: 1250 degrees C/12 h homogenization, 1150 degrees C/6 h solution treatment, and 900 degrees C/4 h + 750 degrees C/16 h two-step aging treatment. The alloy samples were prepared by vacuum induction melting. After the above heat treatment, the DSC analysis results show consistency with the calculated phase transition rules. SEM and XRD results show that the equilibrium phase of the alloy is typical gamma+gamma' two-phase structure.
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RARE METAL MATERIALS AND ENGINEERING
ISSN: 1002-185X
CN: 61-1154/TG
Year: 2021
Issue: 1
Volume: 50
Page: 235-241
0 . 5 3 7
JCR@2021
0 . 6 0 0
JCR@2023
ESI Discipline: MATERIALS SCIENCE;
ESI HC Threshold:142
JCR Journal Grade:4
CAS Journal Grade:4
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ESI Highly Cited Papers on the List: 0 Unfold All
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30 Days PV: 0
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