Machining performance of cermets with alternative binders for milling

Ti (C, N)-based cermets are widely employed in continuous finishing operations of metal cutting owing to their high hardness, superior oxidation resistance, and chemical stability compared to WC-Co based carbides. Nevertheless, their use in interrupted cutting processes such as milling remains restricted due to their inherently low fracture toughness, which often results in brittle-like failure. In the present study, alternative binder systems consisting of Co–Ni and Co–Mo were explored to enhance the mechanical properties of cermets. These modified binder compositions improved fracture toughness and overall strength, leading to significantly better milling performance compared with conventional cermets containing pure Co binders. Face milling experiments on quenched and tempered 42CrMo4 steel (35 HRC) demonstrated that cermets with alternative binders exhibited superior cutting performance in the uncoated and CVD coated states. Moreover, comparative evaluations with a standard WC-Co cemented carbide revealed that coated cermet with Co–Mo binder showed higher tool life in the study, under identical testing environments. The evaluations were conducted under both dry and coolant-assisted machining environments.