Inconel 718–Copper bimetallic joints fabricated by 3D multi-material laser powder bed fusion for aerospace components

Abstract

Usually, aerospace components are subjected to high demanding operating conditions in terms of mechanical and thermal stresses. The structural integrity of these components is assured by the use of high strength and temperature-resistant materials such as Inconel alloys. However, these alloys are known to have low thermal conductivity, which makes it difficult to extract heat from inside the component. Copper-based alloys are widely used in the aerospace field due to their high thermal conductivity, high strength, good ductility and corrosion resistance. A 3D multi-material Inconel 718 – Copper solution was produced by laser powder bed fusion to be applied on a rocket engine wall aiming to improve its heat extraction ability. This approach combines high strength Inconel 718 and high thermal conductivity Copper in a single part, produced at once. The individual Inconel 718 and Copper zones and interface transition zone features were assessed in terms of metallurgical bonding and mechanical behaviour. This 3D multi-material Inconel 718 – Copper solution seems to be a promising approach since the two materials have a well-defined interface with no substantial defects. Inconel 718 and Copper seems to be capable to maintain its most important individual properties, high strength and high thermal conductivity.