Dataset of "Sustainable Strengthening of CoCrFeNiMn High-Entropy Alloy Using NbC/Nb Composite Synthesized from Recycled Carbon Precursors"

This study presents a sustainable approach to the synthesis of niobium carbide (NbC) using carbon obtained from thermal plasma valorization of waste polypropylene, followed by its application as a ceramic reinforcement in CoCrFeNiMn high-entropy alloys (HEAs) produced via powder metallurgy Pure niobium powder and carbon soot were mechanically alloyed as raw materials in Nb: C ratios of 1:1 and 1:2 under high-energy ball milling for up to 8 hours, both with and without n-heptane as a process control agent (PCA). Phase formation was monitored using X-ray diffraction (XRD), while scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were employed to characterize the particle morphology and composition. The absence of n-heptane favored NbC formation and prevented pyrophoric oxidation, with the 1:1 Nb:C ratio yielding approximately 19 wt.% NbC after only 4 hours of milling. optimized NbC powders were subsequently incorporated into CoCrFeNiMn HEAs at 5, 10, and 15 wt.% and consolidated by spark plasma sintering (SPS) at 1000 °C under 80 MPa. Mechanical testing showed that NbC reinforcement moderately increased hardness and compressive strength and significantly enhanced wear resistance due to the hard carbide phase and refined microstructure. Overall, the results demonstrate that NbC synthesized from waste-derived carbon can serve as an efficient and environmentally responsible reinforcement for HEAs, supporting circular-economy strategies while offering insights into carbide formation kinetics, phase evolution, processing optimization, and composite performance.