Displacement modeling for liquid cast forming process development considering microstructure evolution

This study presents a liquid cast forming process enabling thin-walled aluminum structures (1–3 mm) by combining sand casting flexibility with controlled melt displacement above the liquidus temperature. Unlike semi-solid processing requiring forces of 40–80 MPa, this liquid-phase approach achieves wall thicknesses below the conventional sand-casting limit of 4–6 mm with negligible forces (<10 N), preserving sand mold integrity. An energy balance model predicts transient temperature fields during punch-induced displacement, incorporating a characteristic displacement ratio ( ζ ) relating surface-to-volume geometry to process window duration. Experimental validation using EN AC-AlSi7Mg0.3 demonstrated reliable production of 1–3 mm wall thicknesses at punch velocities of 2.5–15 mm s −1 and casting temperatures of 680–745 °C. Model predictions showed good agreement with experimental data (<5 % deviation) for processes above the liquidus temperature (615 °C). Microstructural analysis revealed secondary dendrite arm spacing predominantly influenced by wall thickness (30 % increase from 1 to 3 mm) and punch velocity. The forming zone exhibited 29 % finer microstructure compared to non-deformed regions due to enhanced heat extraction through direct punch contact.