Low-temperature formation of ternary carbide Fe3M3C (M=Mo, W) assisted by mechanical activation

Ternary carbides, Fe3Mo3C, Fe3W3C and Fe6W6C formed from the powder mixtures of Fe/M/C=1:1:1 (M=Mo, W), which were ground for 3 h in a planetary ball mill and subsequently heated at a temperature of 700–800°C. The amount of these carbides increased with an increase in the heating temperature. In contrast, when the samples, which were ground for 0–1 h, were heated to 700–1100°C, Mo2C and WC formed exclusively. From the results concerning the effects of mixing ratio, grinding time and heating temperature of the Fe/M/C (M=Mo, W) samples on the formation of ternary carbides, it was found that the formation of Fe3Mo3C, Fe3W3C and Fe6W6C strongly depends on the mixing homogeneity, the intimate contact and the activated state of the Fe, Mo (or W) and C grains, finely ground by ball milling.