Rapid quenching creates a that transforms into a metastable phase. In Al‑Si alloys, this can produce a fine‑grained dendritic network with suppressed silicon plate formation . The resulting microstructure has a higher nucleation barrier for melt re‑fusion, allowing the skin to act as a thermal shield .
The final product is a monolithic casting where the originates from the first pour and the outer shell (a few hundred micrometres thick) originates from the repack filler, now bonded to a hardened substrate. woodmancastingx 23 03 05 esa dicen casting hard repack
The technique reduces (fewer scrap castings) and energy consumption (only one high‑temperature melt). A life‑cycle analysis of a typical 500 kg gearbox housing showed a 12 % reduction in CO₂ emissions relative to a standard two‑pour casting approach. Rapid quenching creates a that transforms into a