Wear and high-temperature stability of TiCN-WC-Co-Cr3C2-HfC-Si3N4 cermets

Effect of Si3N4 Additive on Microstructure and Mechanical Properties of Ti(C,N)-Based Cermet Cutting Tools

“…Diffusion throughout the oxidation stage led to lower rates of weight gain over time. For the Ti(C,N)-based cermet sample with a 2 wt.%, the addition of Si 3 N 4 exhibits optimum thermal stability that withstands a high heating temperature of 800 °C for 10 h. It can be explained as the formation of oxides; Si 3 N 4 has the ability of thermal resistance [ 8 , 43 ]. Moreover, the relationship between the rate of weight gain and time can be modeled using the following equation [ 44 ]: where Δ m represents the increase in mass, A s denotes the surface area, K p stands for the oxidation rate constant, t is the oxidation time, n represents the oxidation exponent, and c is a constant term.…”

“…Furthermore, it possesses the advantages of both ceramics and metals, characterized by a core/rim structure [ 7 ]. The core–rim structure has a significant impact on the fracture toughness, where the rim is made up of different particles, including tungsten carbide (WC), that inhibit grain growth for Ti(C,N) [ 8 ]. The properties of cermets depend mainly on the additives, which are utilized to boost their high hardness and wear resistance properties and minimize the limitation of their low fracture toughness [ 9 ].…”

“…Furthermore, Si 3 N 4 has the ability to form a solid solution with Ti(C,N), resulting in a finer microstructure and higher mechanical strength. This results in cermets that are more resistant to deformation and can keep their cutting edge for longer periods of time, extending tool life and enhancing machining efficiency [ 8 ]. In summary, adding Si 3 N 4 to Ti(C,N)-based cermets has various benefits, including increased hardness, toughness, and thermal stability.…”