Investigation of strategies to prevent crack formation in the hybrid-additive manufacturing process of tool components using directed energy deposition

Abstract

The ever-increasing variety of products and variants in the automotive industry requires a high degree of flexibility in production processes. In this context, additive manufacturing processes offer a promising approach. In the area of toolmaking, the directed energy deposition process (DED) is currently used for surface repairs and geometry modifications. Moreover, the hybrid-additive manufacturing of tool components represents a novel approach to a cost- effective and resource efficient production. A major challenge is the heat input into the component, as this impairs the contour accuracy and leads to the formation of cracks in the bonding zone. The aim of this paper is to develop an optimized manufacturing strategy to minimize residual stresses and therefore cracks in the bonding zone. In this context, welding specimens with an adapted laser power are additively manufactured. Furthermore, the geometry of the welding specimens is adjusted to minimize notch stresses in the first layers. The specimens are analyzed metallographically to determine the formation of cracks in the bonding zone. Finally, the results are used to manufacture a hybrid-additive tool component.