This study aimed to improve the precision and flexibility of temperature field control in conventional directional solidification (D–S). We propose an innovative digital heating method (DHM), which arranges microheating elements on the crucible surface, allowing for rapid and precise control. Each element is independently controlled by “on” and “off” states, enabling flexible D–S control and energy efficiency. Through mathematical modelling, we established the theoretical feasibility of DHM. In the experiments, a low-temperature Ga-In-Sn alloy was used as the experimental material in a polymethyl methacrylate (PMMA) crucible, and heating elements with different densities and layouts were tested for D–S. The main findings are as follows: First, DHM successfully achieves D–S and can form phase transition interfaces of different morphologies. Second, different element densities and layouts have minimal impacts on normal ingot casting, providing higher design flexibility. Additionally, we discovered that a staggered row layout of heating elements accelerates the solidification rate, whereas a staggered column layout favours the solidification of flat phase transition interfaces. This study presents an innovative approach for D–S heating and provides a low-carbon solution for future research in this field.
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