Deep drawability of additively manufactured sheets with a structured core

Abstract

The deep drawability of additively manufactured stainless steel sheets with a core structure is investigated. By fracture forming limit diagrams it is shown that the additively manufactured sheets reveal good formability. The deep drawing process is analyzed numerically and the numerical models are validated experimentally. The main failure mode is a fracture of the face sheets. No severe deformation of the core structure was encountered, leading to the fact that the parts keep their structural integrity after the deep drawing process. It is shown that the process forces can reasonably be predicted by a modified Siebel’s method. A process window diagram is derived, e.g. showing a maximum deep drawing ratio βmax = 1.4 for honeycomb structures with a relative core density of ρcore = 0.22.