Improved Ambient and High‐Temperature Strength of Cast Hypoeutectic Al–Ce–Mg Alloy Through Multiple Strengthening Mechanism by Extrusion and Sc, Zr Microalloying

The as‐cast Al–Ce–Mg alloy exhibits decent room‐temperature strength and medium‐temperature thermal stability, attributed to the load‐transfer effect of coarsening‐resistant Al 11 Ce 3 eutectic phases and Mg‐induced solid‐solution strengthening, but its strengthening potential is limited by inherently coarse cast microstructure. To address this, this study refines Al 11 Ce 3 via simple hot extrusion and further enhances strength by incorporating Sc/Zr—elements forming L1 2 ‐structured Al 3 (Sc,Zr) coherent nanophases—with extrusion fragmenting coarse Al 11 Ce 3 , inducing a heterogeneous fine/coarse‐grain lamellar structure and retaining the Al 3 (Sc,Zr)‐driven refinement of primary α‐Al and eutectic lamellae postprocessing. Performance wise, as‐cast Al–Ce–Mg(‐Sc–Zr) has 150 MPa strength; extruded Al–Ce–Mg reaches 246 MPa (room temp) and 112 MPa (250 °C); aged‐extruded Al–Ce–Mg–Sc–Zr excels with 400 MPa (room temp), 215 MPa (250 °C), and ductile fracture. Quantitatively, extrusion boosts Al–Ce–Mg's room‐temperature strength by ≈66%, while Sc/Zr microalloying adds 60% more and nearly doubles high‐temperature strength, with the alloy integrating grain‐refinement, solid‐solution, Al 11 Ce 3 particle, and precipitation strengthening—supported by hot extrusion for low‐cost, large‐scale industrial production.