Microstructure evolution and Corrosion behavior of solid solution strengthened (Ti, La)(C,N)-based cermet

(Ti,La)(C,N)-based solid solution strengthened cermet is prepared using carbonitride complex powders (Ti,La)(C,N) by powder metallurgy method and subsequent solid solution treatment. The structure characterization is performed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that (Ti,La)(C,N)-based cermet has the typical core-rim structure. The solid solution treatment results in the diffusion of Mo elements towards the inner rim, leading to the increase of Mo content there. Additionally, the characteristic diffraction peaks of (Ti,La)(C,N) shift to higher angel and exhibit higher crystallinity in comparison to that of Ti(C,N)-La cermet. Corrosion behavior of (Ti,La)(C,N)-based cermet is investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements in 1M NaOH solution. (Ti,La)(C,N) cermet exhibits better corrosion resistant performance with lower corrosion current density (Icorr, 7.03μAcm -2 ) and larger charge transfer resistance (Rct, 2.8E+03Ω.cm 2 ) than Ti(C,N)-La cermet.