Vapor Deposition of Molybdenum-tungsten Alloys.
Electrodeposition and Surface Treatment Elsevier Sequoia S a Lausanne Switzerland 2:12 pages
Binary alloys of molybdenum and tungsten were prepared by the Bureau of Mines in laboratory-scale experiments by hydrogen reduction of their vaporized hexafluorides. Near-optimum deposition parameters were determined, and the nature of the deposited alloys was investigated. Dense, homogeneous alloys were codeposited between 650 deg. and 750 deg. C with a reduction efficiency of more than 75 pct. The alloy composition was uniform when the hydrogen ratio in the gas feed mixture did not exceed three times the stoichiometric requirement. Regulating the proportions of the metal hexafluorides in the gas feed provided a large degree of control over the composition of the deposit. Hardness of the deposits varied directly with the proportion of excess hydrogen in the gas feed and with the weight-percent of tungsten in the alloy. Hardness was not affected by deposition temperature over the range of 650 deg. to 750 deg. C for specimens of similar composition. Extreme brittleness and unsuitable physical shapes of the alloys prevented tensile strength measurements.
Electrodeposition and Surface Treatment, Elsevier Sequoia S.a., Lausanne, Switzerland, V. 2