The current work characterizes the microstructure and mechanical properties of two arc melted Co-Ni-based superalloys containing in atomic percent: 1) Co-40Ni-10Al-7.5W-10Cr-3Ta-0.06B-0.6 C and 2) Co-40Ni-10Al-7.5W-10Cr-3Nb-0.06B-0.6 C. These two materials named 3Ta and 3Nb, respectively, were characterized by X-Ray diffraction analysis, differential scanning calorimetry, scanning electron microscopy, energy dispersive spectroscopy, electron backscatter diffraction and transmission electron microscopy. Furthermore, compression tests were performed from room temperature up to 1000 °C. The 3Ta and 3Nb alloys showed different as-cast microstructures that were confirmed by microstructural characterization and Scheil simulations. The phase transformation temperatures of minor phases were measured and calculated using a thermodynamic approach and some discrepancies observed on the calculated γ′-solvus temperatures reflect that the thermodynamic description of γ′ phase does not take into account the strong partition effect of Ta, Nb and Ti into γ′. As shown by DSC results, the γ′ phase was stable for both alloys up to 1000 °C, being the main reason for the 3Ta and 3Nb alloys to keep the yield stress above 500 MPa.

当前的工作表征了两种电弧熔化的Co-Ni基高温合金的微观结构和力学性能，这些合金的原子百分数为：1）Co-40Ni-10Al-7.5W-10Cr-3Ta-0.06B-0.6 C和2）Co-40Ni -10Al-7.5W-10Cr-3Nb-0.06B-0.6C。分别通过X射线衍射分析，差示扫描量热法，扫描电子显微镜，能量色散谱，电子背散射衍射对这两种材料分别命名为3Ta和3Nb和透射电子显微镜。此外，从室温到最高1000°C进行了压缩测试。3Ta和3Nb合金显示出不同的铸态微观结构，这已通过微观结构表征和Scheil模拟得到了证实。固溶线温度反映出γ'相的热力学描述没有考虑到Ta，Nb和Ti对γ'的强烈分配作用。如DSC结果所示，两种合金在高达1000℃的温度下γ′相都是稳定的，这是3Ta和3Nb合金将屈服应力保持在500 MPa以上的主要原因。