Magnetic and mechanical properties of TiC–xTiN–15MC–yNi (MC = Mo₂C, WC) cermets

The present work investigated magnetic and mechanical properties of TiC–xTiN–15MC–yNi (wt.%, MC = Mo₂C, WC, x = 0, 3, 6, 9, 12, 15, and y = 20, 40) cermets. Room-temperature (RT) saturation magnetization Ms of Mo₂C-containing and WC-containing cermets decreased with increasing x, and that of Mo₂C-containing cermets was lower at the same x and y. Ferromagnetism disappeared at RT for Mo₂C-containing cermets regardless of x and y and for WC-containing cermets at x = 15 for y = 20 and x ≥ 12 for y = 40, mainly due to high total content of non-magnetic Mo (or W) and Ti in binder phase. At x = 15, Curie temperature Tc of Mo₂C-containing cermets decreased to about 97 K for y = 20 and 16 K for y = 40. For Mo₂C-containing cermets, transverse rupture strength (TRS) and hardness reached the maximum at x = 6 for y = 20, and they increased with increasing x for y = 40. For WC-containing cermets, TRS reached the maximum at x = 6 whereas hardness decreased slowly with increasing x for y = 20, and TRS and hardness reached the maximum at x = 12 and 6 for y = 40, respectively. TRS and hardness of Mo₂C-containing cermets were higher than those of WC-containing cermets at the same x and y, except x = 0, 15 for y = 20, mainly due to stronger ceramic grain refinement strengthening effect and stronger substitutional solid-solution strengthening effect of binder phase.