Solidification‐Derived Intermetallic Architectures in Heat‐Resistant Aluminum Alloys: A Review

Conventional precipitation‐strengthened aluminum alloys often lose load‐bearing capacity above approximately 300 °C as matrix softening accompanies precipitate coarsening or dissolution. Solidification‐derived intermetallic architectures offer an alternative route to elevated‐temperature strength through thermally stable lamellar, fibrous, cellular, divorced, or three‐dimensional networks. This review examines heat‐resistant aluminum alloys containing eutectic, near‐eutectic, primary‐phase‐plus‐eutectic, and rapidly solidified eutectic‐like architectures. A manufacturing‐process‐aware framework links alloy chemistry, local thermal history, intermetallic architecture, and defect population across casting, laser powder bed fusion, electron beam powder bed fusion, laser directed energy deposition, and wire arc additive manufacturing. Evidence is categorized into phase stability and hardness retention, instantaneous high‐temperature strength, creep and rupture, fatigue, and component‐scale qualification. Cross‐family comparisons show that refined spacing alone does not ensure heat resistance. Sustained performance also requires sufficient phase fraction, stable morphology and connectivity, matrix strength, interfacial integrity, and tolerance to route‐specific defects. Available studies demonstrate condition‐specific capability within parts of the 300–400 °C range, but the evidence remains uneven and often derives from unmatched test conditions. The resulting family–route–condition framework provides transferable reporting descriptors and qualification priorities without equating thermal stability with structural capability under sustained loading.