Synthesis of TiC/Mg composites with interpenetrating networks by in situ reactive infiltration process

In this paper, a novel and cost-effective processing route, in situ reactive infiltration technique, was utilized to fabricate titanium carbide reinforced magnesium matrix composites (TiC/Mg) with interpenetrating networks. In this process, the ceramic reinforcement phase TiC was synthesized in situ from elemental powders of Ti and C without any addition of third phase metal powder, and the molten Mg can penetrate the preform of (Tip + Cp) by capillary force. By simply controlling the relative density of the predetermined preform, the volume fraction of the in situ synthesized reinforcement with interpenetrating network can be tailored, which was supported by experimental and theoretical comparison for the intrinsically volumetric shrinkage of the in situ formed TiC phase before and after the in situ reaction. Calculation of the lattice constant of the in situ formed TiC phase showed that TiC has a variable stoichiometry of C/Ti depending on the processing conditions and initial particle sizes of the elemental powders.