Multi-material Inconel 718 parts with highly conductive copper cooling channels for aerospace applications

Abstract

Multi-material parts can offer valuable solutions to engineering problems when compared to single materials. The conceptualization of a multifunctional Inconel 718 (IN718)–Copper (Cu) solution aims to improve the heat extraction capacity of an aerospace component. High-strength IN718 was used as the base material and highly thermal conductive Cu was employed for internal cooling channels. The cooling channels are produced by electrical discharge machining (EDM) and subsequently filled with Cu to be sintered by hot pressing (HP). The morphological, microstructural, hardness, and thermal properties of the hot-pressed multi-material IN718–Cu specimens are studied to evaluate the feasibility of HP processing as a viable manufacturing approach for these multi-material solutions. The multi-material IN718–Cu specimens presents a well-defined design with good metallurgical bonding between the two materials and a thin diffusion region is found, assuring the final properties of each individual material. The Vickers’ microhardness of IN178 and Cu are in accordance with the reported for conventional processes which indicates good densification. The thermal conductivity of the multi-material IN718–Cu specimen is 25% higher than mono-material IN718, which can be a significant improvement in the thermal efficiency of an aerospace component.