Reaction synthesis of Ti3SiC2 phase in plasma sprayed coating

This investigation focuses on the feasibility of reaction synthesis of Ti3SiC2 phase using plasma spraying of powder mixture of Ti, SiC and graphite. In-flight particle diagnostics suggested that dwell (reaction) time of these powder mixture is very short (∼10-4 s) during plasma spraying. Phase identification and microstructural characterizations of the as-sprayed coatings were conducted using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Thermodynamic calculations on Ti-SiC-C system were also made. Reaction mechanism of Ti3SiC2 synthesis during plasma spray is proposed. Although relatively lower volume percentage of Ti3SiC2 (∼15-19%) phase was found in the plasma sprayed coating, reaction synthesis of Ti3SiC2 phase using plasma spray provides a potential processing technique to fabricate Ti3SiC2 as a protective coating on large engineering components.