Heat‐Resistant Copper Alloys for Extreme Thermal Environments: Mechanisms, Architectures, and Design Strategies

ABSTRACT

Copper (Cu) and copper‐based alloys are indispensable in high‐heat‐flux systems, such as aerospace propulsion, fusion reactors, and advanced power electronics, due to their high thermal conductivity and good manufacturability. However, extreme service conditions increasingly demand not only high thermal conductivity but also elevated‐temperature strength and long‐term microstructural stability. Under prolonged thermal exposure, conventional strengthening mechanisms, including solid solution strengthening, precipitation strengthening, grain refinement, and dislocation strengthening, gradually deteriorate. Consequently, recovery, recrystallization, grain growth, and precipitate coarsening eventually cause softening. This review examines recent advances in heat‐resistant copper alloys from a mechanism‐oriented perspective, emphasizing the intrinsic link between strengthening and thermal stability. Current strategies are classified into three principal pathways: stabilized precipitation systems, geometrically confined layered or lamellar structures, and interface‐engineered alloys with thermodynamically stabilized phase boundaries or amorphous intergranular films. Their mechanisms, advantages, and limitations are comparatively analyzed with a focus on suppressing high‐temperature softening while preserving thermal conductivity. Heat resistance is argued to depend not on peak strength, but on the persistence of strengthening phases and interfaces under diffusion‐controlled conditions, highlighting the importance of stable interface architectures and microstructural longevity.