Synthesis and Densification of Monolithic Zirconium Carbide by Reactive Hot Pressing

Synthesis and densification of monolithic zirconium carbide (ZrC) has been carried out by reactive hot pressing of zirconium (Zr) and graphite (C) powders in the molar ratios 1:1, 1.25:1, 1.5:1, and 2:1 at 40 MPa, 1200°–1600°C. Monolithic ZrC could be synthesized with a C/Zr ratio ∼0.5–1.0 and the post heat‐treated samples have the lattice parameter in the range 4.665 to 4.698 Å. Densification improves with an increasing deviation from the stoichiometry. Fine‐grained (∼1 μm) and nearly fully dense material (99% RD) could be obtained at a temperature as low as 1200°C with C/Zr ∼0.67. Microstructural and XRD observations suggest that densification occurred at low temperatures with nonstoichiometric Zr–C powder mixtures.