A theoretical model for yield strength anomaly of Ni-base superalloys at elevated temperature

•The temperature-dependent antiphase boundary energy is established.•A theoretical model for yield strength anomaly of Ni-base superalloys is developed.•The model is supported by several Ni-base superalloys.•The study provides a quantitatively theoretical characterization method.

In this study, the temperature-dependent antiphase boundary energy is established from a view of energy conservation. Subsequently, a theoretical model for yield strength anomaly of Ni-base superalloys at elevated temperature is developed on the basis of pre-existing yield strength model and traditional precipitation strengthening theories. The model is verified at different temperatures by comparison with experimental data of several Ni-base superalloys. The excellent agreement between predictions and experiments shows a good prediction ability of this model. This study provides a quantitatively theoretical characterization method for yield strength anomaly of Ni-base superalloys at elevated temperature.