An Overview of Gamma Prime Precipitates Rafting in Ni-Based SC Superalloys: Degradation Kinetics, Modeling and Relations with Mechanical Properties

Abstract

Single crystal (SC) Ni-based superalloys are widely used as the crucial components manufacturing in the turbine blades and land-based gas turbines due to their high tensile strength, stability, and thermal efficiency etc. Microstructure degradation such as rafting, is an essential phenomenon that affects the mechanical properties of the materials in severe service environment to some extent. Hence, it is significant to understand the kinetics of rafting. Besides, quantitative analysis methodology of degradation kinetics investigation is also important. In present overview, specific differences of coarsening and rafting are illustrated in clear comparisons and reviewed to reduce ambiguity in the research works. Subsequently, a new technique which can effectively enhance the experimental efficiency during Ni-based superalloys investigation is introduced. Two classical degradation models to analyze the rafting kinetics are additionally evaluated and compared. Finally, the influence of rafting on the mechanical properties and recent experimental results related are discussed.