(Invited) Chemical and Microstructural Reaction Paths in High-Temperature Alloys in Contact to Molten Salts

Abstract

Molten salts for thermal energy storage applications have gained attention in recent years. Simultaneously, demands on salt melts are also getting higher: higher thermal stability, availability, and economic feasibility.Maybe the most crucial factor, however, is the possibility to match a suitable containment material for salt melts. By increasing operation temperature, material degradation processes commonly accelerate beyond tolerable thresholds. These thresholds are referring to material integrity, strength, and local attack.It turns out that every salt melt hereby reacts along characteristic pathways influencing alloys’ surface chemistry and underlying microstructures to very deep levels.High-temperature alloys depend on their carefully balanced elemental compositions. During this presentation, we will explore how subtle salt-induced compositional shifts have a large and rapid influence on microstructural properties in alloys and thereby on their performance assessment.