Preparation and sintering of fine molybdenum powder

The reduction conditions necessary to prepare fine molybdenum powders from ammonium dimolybdate (ADM) powder were studied in the laboratory. Milling of the ADM, the use of low reduction temperatures, a low bed depth for reduction of ADM to MoO2 powder, and a subsequent deeper bed depth for reduction of MoO2 to Mo yielded finer powders. In laboratory studies using sintering times of 2, 5 and 8 h in vacuum, the finer powders sintered to equivalent densities in 3 h shorter sintering times than coarser powders. (Auth.)