Simultaneous Synthesis and Sintering of Chromium Carbide (Cr₇C₃) Powder by Spark Plasma Sintering Method

Abstract

Chromium carbide (Cr₇C₃) ceramics have been synthesized and sintered simultaneously from a mixture of Cr (-2μm^φ) and C (-5μm^φ) powders by spark plasma sintering method. Dense ceramics were obtained and are composed of single-phase Cr₇C₃ with a small amount of Cr₂O₃, which originates from a trace amount of oxygen adsorbed on as-received starting powders. Cr₇C₃ ceramics sintered at 1350°C have 99.5% relative density and fine structure with 2.5μm grain size. They exhibit excellent mechanical properties: bending strength σ_b 540 MPa, Vicker's hardness H_v 16.9 GPa, and fracture toughness K_IC 5.3 MPa⋅m^1/2.