Characterization of Thermo-mechanical parameters of Nickel-Based single crystal superalloys under high-temperature by modified I-DIC method

Understanding the evolution law of thermo-mechanical parameters of nickel-based single crystal superalloys under high-temperature is significant for modeling, application, and structural optimization. In this study, a modified integrated digital image correlation (I-DIC) method is developed to characterize its thermo-mechanical properties. Particle Swarm Optimization (PSO) and Gradient-Based optimization algorithm are introduced to the modified I-DIC method. The orthotropic thermo-mechanical constitutive model for nickel-based single crystal superalloys is evaluated and the relative five constitutive parameters at temperatures ranging from 600 ℃ to 1000 ℃ are inversed simultaneously by the modified I-DIC method. Comparison between experiments and simulations confirms that the suggested model is reliable and the modified parameter inversion method is accurate and effective. The results show that the parameters vary with temperature. The coefficient of thermal expansion (CTE) and Poison's ratio increased with increasing temperature, while Young's modulus and shear modulus decreased with increasing temperature.