Production feasibility of bimetallic components via two additive manufacturing approaches

Abstract

Localized property behavior has been on the upside in recent years regarding aerospace, automotive, and machinery industries, and thus it set the motivation for joining two dissimilar materials. Six bimetallic components were manufactured through two laser metal additive manufacturing (MAM) methodologies. Laser powder bed fusion (LPBF) was employed to engineer bullet shape Inconel 718 substrates. Afterwards, stainless steel 316L was poured over them via blown powder direct energy deposition (DED). Preliminary studies were carried out to optimize the samples volumetric integrity to favor good mechanical bonding based on volumetric and linear energy density. 37.3 J/mm3 and between 21.5 and 26.2 J/mm for LPBF and DED, respectively, generated the least porosity. A reasonable 81.44% junction integrity was reached with a columnar to planar transition. Intermetallic compound (IMC) diffusion was noticed yet Vickers microhardness values were in accordance with literature. Inherent discrepant thermal properties remained a challenge though. The analysis of other formed IMCs and further processes optimization are forthcoming work. The described findings are meant to set the basis for joining unrelated metals for producing components without the need of external joining components or complementary procedures