Integration of spray-formed AISI H13 overspray powder in additive manufacturing to enable a circular ecosystem

Abstract

Overspray powder is a bi-product of the spray forming process and is commonly considered as scrap material. This study, however, assessed the feasibility of the use of spray-formed AISI H13 overspray as powder feedstock for LPBF as part of a circular economy concept. The overspray powder presented a suitable particle size distribution for LPBF applications and showed the capability of being printed crack free. X-ray diffraction was used to show that ferritic/austenitic overspray powder transformed into a martensitic austenitic microstructure in the as-printed conditions. Furthermore, texture analysis revealed a preferred crystallographic orientation in <100> parallel to the build direction for martensite while the retained austenite presents a preferred orientation in <110> along the build direction.