[T15] Hard Materials

[17F-T15-09] Powder Metallurgy Processing of TiC-FeCrMo Cermets: Sintering and Thermal Treatments

*J. M. Sanchez-Moreno^{1, 2}, J. Navarrete-Cuadrado^{1, 2}, T. Soria-Biurrun^{1, 2}, L. Lozada-Cabezas^{1, 2}, F. Ibarreta-Lopez³, R. Martinez-Pampliega³ (1.CEIT-BRTA, Spain, 2.TECNUN-UNAV, Spain, 3.FMD CARBIDE, Spain)

Keywords:TiC cermets, Vacuum sintering, Heat treatments, CCT curves

Vacuum sintering of TiC-FeCrMo cermets increases as the pressure of the furnace chamber decreases. This is due to a more efficient reduction of powder oxides. Ar injection above 1300ºC avoids iron evaporation. However, some gas is entrapped leaving residual porosity after sintering. High carbon contents lead to precipitation of undesired M₇C₃ carbides at the (Ti_1-x,Mo_x)_yC_z - metal interface and the formation of retained austenite. Continuous cooling experiments prove that TiC-FeCrMo cermets are suitable for air-quenching, simplifying their fabrication. The bainitic transformation is sensitive to the carbon content of the matrix. These materias exhibit complex microstructures comprising martensite, ferritic bainite, M₇C₃ and M₂₃C₆ carbides. TiC-FeCrMo cermets with optimum heat treatments present a combination of hardness, strength and toughness in the range of those reported for WC-Co cemented carbides used as roller guides in hot rolling applications.