Mechanical behavior and constitutive model of laser clad Inconel 625 alloy under high temperature and high strain rate

In order to study the mechanical behavior of laser clad Inconel 625 (IN625) alloy under high temperature and high strain rate, laser clad IN625 alloy samples were prepared, and the samples were obtained at four temperatures (25 ℃, 600 ℃, 800 ℃, 1000 ℃ ) and the compressive stress-strain curves under three strain rates (1000 s-1, 2000 s-1, 3000 s-1), and an applicable constitutive model was constructed. The results show that there are elastic and plastic stages in the stress-strain curves of laser clad IN625 alloy at four temperatures and three strain rates. At each temperature, the material yield strength and flow stress increased with the increase of strain rate, showing obvious strain rate strengthening effect. At each loading strain rate, the flow stress and yield strength of the material decrease with increasing temperature, showing a significant temperature softening effect. Based on the stress-strain data and the Johnson-Cook (J-C) constitutive model, the model is modified through fitting of the temperature softening index and strain rate sensitivity coefficient. The model fitting values ​​are in good agreement with the experimental results and can accurately Describe the mechanical behavior of materials.