Mechanism Based Constitutive Modeling Of L12 Single Crystal Plasticity

Ni3Al, an L12 structure intermetallic crystal, is the basic composition of the [gamma]' precipitates in nickel-based superalloys and is a major strengthening mechanism contributing to the superalloys' outstanding high-temperature mechanical properties. Many L12-structure crystals present unusual macroscopic mechanical properties, including the anomalous temperature-dependence of yield strength and strain hardening rate. To date, extensive research has been carried out to reveal the underlying mechanisms. However, none of the resulting models has satisfactorily quantified the macroscopic behavior based on microscopic phenomena. Mechanism-based constitutive modeling and simulation provide an effective method in this respect, assisting in the understanding and development of current existing models, and potentially providing a convenient path for engineering applications. In light of recent theoretical developments and experimental evidence, a single-crystal continuum plasticity model for the L12-structure compound Ni3A1 is developed.