Effect of the medium composition on molybdenum carburization in a glow discharge plasma

The effect of glow-discharge ionized methan-hydrogen medium in the intensity of molybdenum carbidization was studied. The relationship between the carbidization intensity, the discharge power (temperature) and methan pressure was determined. Carbudization takes place up to formation of Mo2C phase at 1400 - 2000 deg C (at the discharge power of 30 - 90 VA/cm2) if the partial pressure of methan does not exceed 0.5 mm Hg. At a temperature over 1600 deg C (at the discharge power of 60 VA/cm2) and partial pressure of methan of 0.5 mm Hg the interaction between carbon and molubdenum is discontinued. It is shown that molybdenum carbide may be formed below a metal layer. The mechanism of this process is explained