Investigation on microstructure and mechanical properties of Mo₂FeB₂ based cermets with and without PVA

Mo₂FeB₂ based cermets with and without PVA have been investigated by x-ray diffractometry (XRD), x-ray photoelectron spectroscope (XPS) and scanning electron microscopy (SEM). The density and transverse rupture strength (TRS) of green compact, relative density, hardness (HRA), fracture toughness (K_IC) and TRS of Mo₂FeB₂ based cermets were also measured. The results indicate that, compared with the Mo₂FeB₂ based cermets without PVA, the density of green compact with PVA can be improved slightly at the same pressure. However, the much higher TRS is obtained for the green compact without PVA. Meanwhile, Mo₂FeB₂ particles exhibit the finer and less congruity feature for Mo₂FeB₂ based cermets without PVA. In addition, the higher relative density, hardness, fracture toughness and TRS can be acquired for the cermets without PVA. Obviously, considering the mechanical properties and preparation period of Mo₂FeB₂ based cermets, no adding PVA is the optimized process of powder molding in the manufacture of Mo₂FeB₂ based cermets.