Kinetic Insights Into Boron–Carbon Interaction Under Programmed Heating

ABSTRACT

The investigation of reaction kinetics governing the formation of refractory ceramics remains challenging, primarily because of the limited capability of conventional in situ characterization at elevated temperatures. In particular, the direct solid‐state synthesis of boron carbide (B ₄ C) is characterized by low exothermicity and sluggish diffusion kinetics, and reliable kinetic data remain scarce despite its considerable technological importance. Here, we elucidate the kinetics of fine‐grained B ₄ C formation from a stoichiometric 4B + C mixture under programmed heating. The synergistic effect of the short‐term mechanical activation and rapid heating of the reaction mixture (100°C–2400°C min ⁻¹ ) is demonstrated, leading to the systematic shift in characteristic reaction temperatures. This approach enables, for the first time, the determination of the effective activation energy of the 4B + C reaction under rapid heating conditions. This provides a framework for the synthesis of refractory material powder with regulated microstructure at comparatively reduced temperatures, moreover, extending kinetic investigations to other refractory systems.