Reduction of Molybdenum Hexafluoride by Oxygen on Internal Surfaces of Tubular Products.

Using an experimental setup, it is found that variation of the composition of the gas mixture, taking place during the reduction of molybdenum hexafluoride by hydrogen, is accompanied by the formation of different types of molybdenum deposits along the reaction zone. In order to obtain solid and structurally uniform deposits with a high efficiency of utilization of MoF//6, the temperature of 850-900 C and the content of 20-27 mol. % of MoF//6 in its initial mixture with hydrogen are recommended. The possibility of obtaining uniform molybdenum coatings ( plus or minus 15%) on the internal surface of tubular products up to 600 mm long, with the ratio of d/v approximately equals 0. 7, the presence of the temperature gradient of about 1 degree C/cm of length, and reversal of the direction of flow of the gas mixture is demonstrated.