Distinguishing contributions of metal binder and ceramic phase to mechanical performance of cermets at different temperatures

It is crucial to clarify the effects of the ceramic phase, the metal binder, and temperature on the mechanical properties of WC-Co cermets, as a typical representative of cermet materials, due to highly demanded excellent high-temperature properties under harsh service conditions. Based on uniaxial compression tests and detailed microstructural characterization, this study quantified the deformation characteristics of the ceramic phase and the metal binder at room temperature and high temperatures applying multiple analysis methods. It distinguished different contributions of the ceramic phase and metal binder to the plasticity of the cermets during deformation, and proposed the mechanisms for the plastic deformation of cermets. The results indicated that the dislocation plasticity is the dominant deformation mechanism of the cermets, and the ceramic matrix is mainly responsible for the fracture strength and contributes significantly to the plasticity of the cermets both at room temperature and high temperatures. At high temperatures, grain boundary slip and phase boundary sliding also contribute to the plastic deformation of cermets. • Microstructure evolution and changes in crystal defects of cermets with stress at different temperatures were analyzed. • Dislocation plasticity is the dominant deformation mechanism of cermets at both room and high temperatures. • Grain boundary sliding and phase boundary migration contribute more to plastic deformation of cermets with higher contents of metal binder.