Research Progress on Uneven Cooling in Horizontal Direct Chill Casting of Aluminum Alloys

Traditional vertical direct chill (VDC) casting faces challenges such as discontinuous production and safety risks. In contrast, horizontal direct chill (HDC) casting has gained attention for its continuous operation, enhanced safety, and cost-effectiveness. However, fundamental studies on HDC of aluminum alloys remain limited, particularly concerning quality defects caused by asymmetric cooling within the mold. This article reviews the origins of cooling inhomogeneity in aluminum alloy HDC and the strategies developed to mitigate it, with emphasis on mold design optimization, process parameter control, and modification treatments. Research shows that optimized casting speeds, low-frequency electromagnetic fields, combined magnetic fields, and power ultrasonic techniques can refine grains, reduce surface segregation layer thickness, and suppress solute segregation. Despite these advances, challenges remain, including microstructural defects from uneven cooling, limited effectiveness of grain refiners, and an incomplete understanding of multi-field synergistic mechanisms. Future research should focus on developing multi-physics numerical models to establish quantitative links between external field parameters and solidification structures, creating rareearth-enhanced composite modification methods for greater compositional flexibility, designing modular external field devices to improve energy field uniformity in large ingots, and applying AI-driven multi-objective optimization for precise process control.