Microstructure and phase formation in TiC-TiB2-SiC composites processed by pulsed laser melting

Abstract

The development of high-performance ceramic composites for extreme environments requires advanced processing techniques that can tailor microstructures and explore non-equilibrium phases. This study investigates the synthesis of TiC-TiB2-SiC composites via pulsed laser melting. The influence of powder preparation (dry planetary ball milling vs. wet mixing) and laser parameters on microstructure and phase formation was examined. Results demonstrate that dry milling for 120 minutes produced a homogeneous powder essential for consistent melting, while wet preparation led to inadequate microstructures. Laser processing above a 230 V threshold under a low-reactivity atmosphere achieved full integration of phases. Crucially, the rapid solidification triggered non-equilibrium conditions, yielding a characteristic solidification sequence and, most significantly, the formation of previously unreported peritectic ternary phases identified by EDS analysis. This work establishes pulsed laser melting as a viable route for processing TiC-TiB2-SiC composites and highlights its unique potential for discovering novel non-equilibrium microstructures in complex ceramic systems.