fig20
![Development of robust surfaces for harsh service environments from the perspective of phase formation and transformation](https://image.oaes.cc/6fdf97ea-ef8f-4210-ac0b-4962c57383cc/4323.fig.20.jpg)
Figure 20. Calculated Al-Ni-Si-Y quaternary phase diagrams: (A) isothermal section in the Ni-rich corner at 750 °C; (B) variation of phase fraction along with increasing temperature for sample #2 Ni-12Al-3Si-1Y. The inset in (B) shows the microstructure of sample #2 after annealing at 1300 °C for 24 h, in which the eutectic structure consists of γ’-Ni3Al and β-NiAl. Figure reproduced from Ref.[38] with permission from Elsevier.