Tribological characteristics of conventionally sintered TiCN-WC-Ni/Co cermets against cemented carbide

Present research deals with the tribological behavior of TiCN-WC-Ni/Co cermets with or without TaC in unlubricated sliding at different loads (5-20 N). Commercially available cemented carbide hard material was selected as counterbody to understand the potential of new generation cermets in severe conditions of sliding. Dense TiCN based cermets were processed via conventional sintering whose hardness and fracture toughness varied from 14 to 16 GPa and 8.75-9.25 MPa m1/2, respectively. The size and fraction of adjacent ceramic phase in the microstructure influenced mechanical properties and wear behavior of the cermets. A variation of 79% in steady state coefficient of friction (COF) and 70% in wear rate is found with respect to composition and load. Hard oxide debris particles are responsible for higher COF at low load, whereas their compaction results in the tribolayer formation at high load. Material transfer from cemented carbide ball onto the cermet disc enhanced at high load due to increased contact temperature. The refined size and least fraction of adjacent ceramic phase are attributed for reduced wear in TaC added TiCN-WC-Ni/Co cermet.