ON THE PREDICTION AND ENGINEERING OF MICROSTRUCTURES AND PROPERTIES IN ADDITIVELY MANUFACTURED METALLIC MATERIALS.

The materials science paradigm is to understand, describe, and exploit the fundamental interrelationships that exist between composition, processing, microstructure, and the attending properties of a given material. While this is the objective in theory, it is often a challenge in practice, especially when disruptive technologies provide new ways to manufacture a material. Certainly, additive manufacturing of metallic materials is a disruptive technology. It is necessary that the materials scientist understand the fundamental interrelationships between composition, processing, microstructure and properties in order to use additive manufacturing with a high degree of confidence for engineered applications. This paper will describe both the fundamental aspects associated with the interrelationships for additive manufacturing of metallic materials, as well as provide examples of modeling activities related to additive manufacturing of titanium. The overall framework that will be presented will describe the opportunities that exist to engineer certain microstructures, as well as what governs the boundaries of additive manufacturing. Based upon this framework, it is possible to predict, and possibly engineer: macro-level microstructural characteristics (e.g., residual stress, porosity, texture); microstructural characteristics (e.g., grain size, precipitates); and compositional aspects (e.g., bulk composition, volatilization, solute pickup, partitioning). [ABSTRACT FROM AUTHOR]