Modeling and Simulation of Alloy 718 Microstructure and Mechanical Properties

Alloy 718 is a unique superalloy that has been in use for a number of years. It also has the distinction to be utilized throughout the aerospace and general industrial communities. The applications for this material are often very unique and require tailoring of the microstructure and subsequently the mechanical properties to meet these specific needs. To support optimization of Alloy 718 mechanical properties and performance, considerable work has been conducted by the materials community to develop materials and manufacturing process models to aid in the simulation and prediction of the microstructure and mechanical properties of components produced from this alloy. This paper will review various modeling and simulation tools and applications to Alloy 718. This complex alloy is continuing to see optimization efforts through the use of modeling and simulation to support new and enhanced application requirements. Introduction Modeling and simulation tools and computational methods are being developed and used for a wide range of applications. Models that describe the behavior of microstructure evolution are being linked to manufacturing process simulations to enable predictive assessment and analysis for specific component applications. The models that are being created are of various types, including physics-based mechanistic models, experiment-based phenomenological models or input-output data-based statistical models. These computational tools are being applied to nearly every material for the purpose of enhancing material and component capability, and reducing material, process or component development time and/or cost. Materials are currently being designed and optimized through the use of computational tools. [1, 2, 3] Use of computational tools has provided the ability to seek both cost and performance enhancements of new alloys for the broad range of nickel-base superalloy classes for turbine engine disk applications. The application of computational methods can enable the assessment of alloy inherent, manufacturing process and application lifecycle costs, which can open up the ability to holistically design new components for optimum performance and total life-cycle costs. Recent work has shown significant reduction in new alloy development time through the application of computational methods. Similarly, manufacturing processes are being simulated along with material response to enable process optimization and control schemes to produce unique, location-specific designed components, such as hybrid-microstructure (dualmicrostructure) disks for turbine engine applications [4].