Tailor-Made Net-Shape Composite Components by Combining Additive Manufacturing and Hot Isostatic Pressing

Abstract

. A promising production route for high quality tailor-made parts can be established by combining Additive Manufacturing (AM) and Hot Isostatic Pressing (HIP): By using a numerical simulation routine, the shape change during HIP can be controlled. These shape-controlled parts are built by Laser Powder Bed Fusion (L-PBF) and consolidated by HIP. After HIP, they exhibit a net-shape geometry that requires only little or even no post-processing at all. In this study, open thin-walled capsules are manufactured by L-PBF, filled conventionally with metal powder, evacuated and sealed and hot-isostatically pressed. Using this processing route, it is possible to combine different materials for the capsule and the powder filling. If capsule and bulk material are identical, the expensive removal of the capsule after HIP can be omitted. By using two different powders, it is possible to produce composite components with a core of high strength and toughness and a wear- or corrosion-resistant surface layer, offering an alternative and competitive production route to conventional HIP cladding. Here three materials are investigated in different combinations: austenitic stainless steel AISI 316L (DIN X2CrNiMo17-13-3), martensitic tool steel AISI L6 (DIN 55NiCrMoV7) and the wear resistant high carbon steel AISI A11 (DIN X245VCrMo8-5-1). A number of technical challenges need to be addressed: the production of dense, thin-walled capsules by L-PBF; L-PBF of carbide rich steels; and controlling the diffusion between corrosion resistant steel and carbon steel. The success of the new process route is demonstrated by metallographic and geometrical investigations.