CALPHAD aided design of novel ternary Fe-C-P alloys with reduced solidus and liquidus temperatures

A novel low-melting ternary Fe-C-P alloy system was designed via CALPHAD and fabricated using Hydrogen Plasma Arc Melting (HPAM). Differential scanning calorimetry (DSC) and SEM coupled with EDX characterizations confirm excellent agreement with thermodynamic predictions, proving that synergistic C and P additions systematically depress the melting point, achieving a remarkably low liquidus temperature of approximately 972°C due to the formation of continuous, intercellular M 3 P/cementite eutectic steadite phases networks. The extreme thermal profiles of HPAM induce a profound kinetic undercooling lag during solidification. This kinetic barrier optimizes phase evolution, ensuring superior structural connectivity, excellent melt fluidity, and reduced thermal contraction stress. The Fe-C-P alloys provide a versatile metallurgical strategy for casting, brazing, and advanced additive manufacturing at lowered processing temperatures.