Modeling of materials behavior at various temperatures of hot isostatically pressed superalloys

It is very important to be able to predict material behaviors at low and high temperatures for the design and manufacturing of reliable elevated-temperature systems. Superalloys are widely used on most liquid rocket engines for space launch vehicles or gas turbine engines where they experience hot temperature gases and low temperature fluids like liquid oxygen. Hot isostatic pressing (HIP) is one of the manufacturing methods for developing these materials. In this research, three superalloys, HIP Inconel 718, HIP Rene 95, and HIP Astroloy, were investigated at elevated temperatures. Serrated flow induced by dynamic strain aging (DSA) was observed in certain temperature regions where the embrittlement of the materials progressed. A dislocation barrier model was modified to describe the material behavior including dynamic strain aging and creep relaxation effects observed at high temperatures. The suggested model was found to predict well the deformation behaviors of the superalloys from low temperatures to elevated temperatures.

► Experimental results contain Inconel 718, Rene 95, and Astroloy. ► Serrated flow induced by dynamic strain aging was observed. ► Modification of Kock's dislocation barrier model was developed. ► DSA effect and relaxation effect have been included in the model.