2003 年 50 巻 5 号 p. 372-376
Chromium carbide (Cr7C3) ceramics have been synthesized and sintered simultaneously from a mixture of Cr (-2μmφ) and C (-5μmφ) 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 σb 540 MPa, Vicker's hardness Hv 16.9 GPa, and fracture toughness KIC 5.3 MPa⋅m1/2.