Microalloying Strategies Enable Heat-Resistant Aluminum Alloys via Microstructural Design at Atomic Length Scale

Aluminum alloys, as core materials for lightweight and low carbon applications, derive their mechanical performance directly from their microstructure. After decades of development, conventional strategies such as adjusting the main alloying elements and optimizing heat treatments have approached their performance limits. Microalloying has emerged as a highly promising approach to refine microstructures and enhance the mechanical properties of aluminum alloys. Its effects originate from atomic scale interactions between microalloying elements, other solute atoms, and vacancies, as confirmed by state-of-art and multi-faceted characterization. The deep understanding of microalloying mechanisms provide an opportunity to boost microstructural design towards advanced Al alloys with enhanced performances. Especially, the heat-resistant high-strength Al alloys that can work at the temperature range of 200°C-400°C are urgently required in modern industries. Microalloying response has showed significant advantages in the development of heat-resistant Al alloys. In this paper, the recent progresses in the microalloying of aluminum alloys are briefly reviewed, emphasizing the effects of microalloying on precipitation behavior, microstructural thermal stability, and mechanical properties. It also highlights the key mechanisms and strategies for regulating these effects. The insights presented aim to support the composition design and microstructural optimization of high-performance and heat-resistant aluminum alloys.