Inconel 718-copper parts fabricated by 3D multi-material laser powder bed fusion: a novel technological and designing approach for rocket engine

Abstract

A home-made 3D multi-material laser powder bed fusion (3DMMLPBF) system was used to produce novel multi-material Inconel 718 (IN718)-copper (Cu) parts with potential to be applied in rocket engines. This innovative approach combines IN718 high strength and Cu high thermal conductivity in a single part, fabricated at once. The main goal of this study was to validate the developed multi-material powder-based manufacturing technology as well as to access both individual material zones and interface transition zone features in terms of metallurgical bonding and mechanical behaviour. The multi-material IN718-Cu specimens revealed a strong metallurgical bonding with a thin gradual chemical transition between two materials. Moreover, no significant pores, cracks or other defects were observed on both individual and interface zones as well as no undesirable powders from the previous layers. IN718 hardness results were in agreement with literature (about 344 HV) and the results obtained for Cu (about 126 HV). The disparity on the hardness results between the IN718 and Cu is coherent with the thin diffusion zone reflected in the chemical compositional analysis. This multi-material material IN718-Cu solution seems to be a promising approach since the two materials have a well-defined interface with no substantial defects; both IN718 and Cu are capable to maintain its most important individual properties, high strength and high thermal conductivity, respectively.