Ambient and high temperature in situ damage evolution in nickel based IN 718 super alloy

In the present work, Lemaitreʹs damage assessment methodology has been applied to predict evolution of damage during tensile test at ambient temperature and at 823 K in nickel based IN 718 super alloy. The damage has been evaluated through apparent elastic modulus measurement from each unloading step during the test. Marked difference was found in damage evolution and operative damage micromechanisms at these test temperatures. Critical points have been identified on the damage evolution curves for room temperature loading condition. Based on these parameters, the damage has been predicted using Lemaitreʹs damage model for high temperature specimen. The damage predicted is found to be in good agreement with experimental curve.