Model-Based Material and Process Definitions for Additive Manufactured Component Design and Qualification

Physics-based materials and process modeling has developed to the point where it is supporting the design and qualification of new components produced by many processes, including additive manufacturing (AM). Combinations of computational models that utilize various material and process parameters for AM processes, and which predict the evolution of microstructure and defects, and location-specific mechanical properties are key elements of what is termed “model-based material definition” (MBMD). These computational tools, when used with integrated, interdisciplinary modeling workflows, provide a holistic engineering framework for additive manufactured materials and processes. Property prediction of printed legacy materials or emerging alloys requires the understanding and control of input powder characteristics and the manufacturing processing path, starting with the feedstock and including, e.g., the local thermal history at scales from individual melt pools to full-scale component geometries. The use of model-based material definitions is critical to capture the spatial variation of processing paths and consequently spatial variations of microstructure and properties throughout the entire volume of printed components. Statistical descriptions of microstructure, whether measured or computed, enable the establishment of statistically equivalent representative volume elements (SERVEs) as discretized sub-volumes of entire component volumes that can be used to subsequently predict local mechanical properties. MBMD enables establishment of component manufacturing and property key characteristics, which can be used as component and process qualification and certification requirements. The alignment of model-guided component testing and associated key characteristics provides for a path for efficient, smart certification and qualification of new AM materials and components. This article is an analysis and demonstration of the application of MBMD to AM materials and components. The MBMD framework described herein is deemed to be an optimal approach for AM component design, manufacture, and qualification.