In-situ alloying of TiC-FeCr cermets in manganese vapour

Abstract

Conventional vacuum sintering is, in general, inappropriate for producing manganese containing cermets because high vapour pressure combined with high sintering temperature of cermets (1400–1600 °C) causes considerable Mn loss through sublimation and evaporation. Sintering in Mn-rich microatmosphere does not only prevent Mn loss but also enables additional in-situ alloying of the binder phase during sintering. We studied alloying of TiC-based cermets bonded with high chromium steels, especially TiC-FeCr and TiC-FeCrMn, during sintering in Mn-rich atmosphere. Sintering in manganese vapour was detected to increase sinterability of the cermets, resulting in the formation of a ~1 mm thick Mn-rich surface layer with homogeneous microstructure while the core region of the material remained unaffected. This surface region of sintered TiC-FeCr and TiC-FeCrMn cermets exhibited increased Mn content and competitive mechanical properties – hardness of ~1150 HV30 and indentation fracture toughness of ~12 MPa·m1/2.

Keywords

• tic cermets
• alternative binder
• sintering environment.