Effect of processing parameters on the mechanochemical synthesis of nanocrystalline molybdenum carbide

• Nanocrystalline Mo2C with a mean crystallite size of 54 nm was synthesized.
• Mo2C magnitude is independent of milling time and carbon content at room temperature.
• Extra carbon content led to further reduction of MoO3 during carbothermal process.

Nanocrystalline molybdenum carbide (Mo2C) was synthesized from commercially pure MoO3 and graphite using high energy planetary ball milling and subsequent heat treatment. X-ray diffraction (XRD), differential thermal analysis/thermogravimetry (DTA/TG) and field emission scanning electron microscopy (FE-SEM) techniques were employed to evaluate powder particle characteristics. XRD results showed that during carbothermic reduction of MoO3, metallic molybdenum is formed as an intermediate phase before the carbide formation. Phase composition of the 20 h milled sample with 90% extra graphite after heat treatment at 1000 °C consists of nano-crystalline Mo2C with a mean crystallite size of 54 nm.