Thermal‐Induced Inelastic Shrinkage and Swelling Deformation of Heat‐Resistant Polycrystalline Nickel‐Based Alloy

The present article focuses on the novel features of the mechanical behavior and properties of the nickel‐based XH73M (EI698‐VD) alloy under conditions of high temperature. The article reveals the unique effects of thermal‐induced deformation phenomena. The experimental results showed that the alloy exhibited shrinkage (up to 0.0928%), as well as oscillating strain at elevated temperatures in the absence of applied load. The temperature dependence of the thermal‐induced deformation process in the range of 400–650 °C is shown. It is established that the strains are nonquasi‐linear. The change in the electrical resistivity and the correlation of electrical resistance with strain have been investigated using in situ conventional four‐terminal potentiometric method. The data obtained is of critical importance in order to prevent accidents, wear, or a decrease in the efficiency of turbines or components that are subjected to high temperatures for extended periods.