Abstract:In order to determine the composition of the novel γ′ 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 calculations showed that: W, Ni, Ta, and Ti can improve the stability of γˊ, W, Ta can increase the precipitation tendency of the harmful phase χ-D019, and Ti and Ni can be suppressed the precipitation of the harmful phases χ-D019 and B2 phase respectively, the alloy composition was 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 γ, γˊ, χ-D019 and Co7Ta2, and the initial precipitation temperatures were 1355 °C, 1169 ° C, 700 ° C, and 288 ° C, respectively. The alloy heat treatment process was formulated: 1250℃/12h homogenization, 1150℃/6h solution treatment, 900℃/4h + 750℃/16h two-step aging treatment. The alloy samples were prepared by vacuum induction melting. After the above heat treatment, the DSC analysis results are consistent with the calculated phase transition rules. SEM and XRD results show that the equilibrium phase of the alloy is typical γ + γˊ two-phase structure.