Chapter Eight - Linking materials systems approach to alloy design and part qualification for laser powder bed fusion additive manufacturing

Abstract

Leveraging the structural fine-tuning capabilities of laser-powder bed fusion (L-PBF) additive manufacturing (AM) requires novel alloys. Furthermore, due to the complex multiphysics involved in L-PBF AM, variation in the attributes of microstructural and macrostructural features of a structural component occurs. This engenders the need for unconventional methods of part qualification. In this chapter, we consider the prospects of incorporating alloy chemistry into the traditional processing-microstructure-property paradigm as outlined by the materials systems approach. We discuss how the resulting modified systems approach may facilitate both alloy design and part qualification in L-PBF AM. The possible variations in several attributes of the structural hierarchy of an L-PBF AM-built component are described, including the variations at the microstructural and the macrostructural length scales. Following the chemistry-processing-structure-property relationships outlined in the modified systems approach, the implications of such variations for printability, mechanical properties, component performance, and part qualification are discussed. Subsequently, consideration of these variations is deemed important for both alloy design and part qualification. A comprehensive ICME-based approach is outlined for establishing the chemistry-processing-microstructure-property relationships. The ICME-anchored modified systems approach may guide the alloy design efforts and may also guide the application experts in various industries in optimizing L-PBF AM parameters and qualifying an L-PBF AM-built component.